Mid-fi Headamp Shootout

Discussion in 'Vinyl Nutjob World: Turntable and Related Gear' started by ogodei, Jun 4, 2021.

  1. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    2,210
    Trophy Points:
    93
    Location:
    Chicago
    This thread documents a comparison of several mid-and-lower-priced headamps I’ve been conducting for several months. The process included both long-term, casual listening to various headamp-phono preamp combos and three shootout sessions, each session featuring a single phono preamp paired against every headamp.

    This post sets up the process and equipment I used.
    The next makes a digression into basic headamp ( and a little bit of SUT) knowledge.
    The third and beyond have my findings on the headamps and some conclusionary thoughts.

    The setup

    [​IMG]

    The headamps I compared were:
    • Muffsy MC Head Amp (DIY kit)
    • Lounge Audio Copla
    • Hagerman Audio Labs Piccolo2
    • Audio Design MCP-1
    • Musical Fidelity AC-1
    • Music Reference RM-4
    The first three are current production amps (the Muffsy is a kit), the last three are out of production but are still well considered and available (occasionally) on the used market.

    Why this comparison and these specific headamps?

    I’ve been asking myself that a lot recently. I acquired several headamps (and SUTs) for no good reason other than “I should listen to this stuff.” Following a discussion in the Phono preamp thread I set out to do a comparison, setting a random price max of $500 USD on the headamps to keep things simple and less expensive for me. I acquired a couple more, started listening and here’s a post about my findings.

    Note this comparison is strictly headamp versus headamp, not versus SUT. That will be another thread. If you’re wondering why I bothered, see my Big Degression post below.

    I’m also making a digression to brain-dump things I’ve learned about headamps, phono-preamps, cartridge loading and gain that I’ve learned along the way which think would be beneficial to know.

    General info about my system and some disclaimers


    I purchased all equipment used in these comparisons (no discounts, no freebies for a promise of a review, etc.) with the exception of the Audio Design MCP-1, graciously lent to me by @k4rstar . My thanks to him for the loan and his patience as I took too much time to get this done.

    The system behind the comparison includes:
    • VPI Classic 4 turntable
    • VPI 12” 3D Tonearm
    • Custom low-capacitance phono and RCA cables
    • Shindo Sinhonia F2A monoblock amplifiers
    • Devore Fidelity Orangutan O/96 speakers
    I used an Ortofon Cadenza Bronze moving coil cartridge for all listening. Some measurements from the manufacturer:
    • Output voltage at 1000 Hz, 5cm/sec. - 0.4 mV
    • Internal impedance, DC resistance - 5 Ohm
    • Recommended load impedance - 50-200 Ohm
    I used 4 different phono preamps at various times during the process:
    • Shindo Massetto
    • Ray Samuels F-117 Nighthawk
    • A modded TC-750
    • Darlington Labs MM6
    The Darlington Labs MM6 didn’t get its own shootout because one of the listener/participants to a preamp comparison I was hosting demanded to take it home for use in his own system. You know who you are. Hopefully the Darlington will reappear in time for comparisons with the MM7.

    In the next post Im on to some basic headamp Q&A. Posts beyond contain findings.
     
    • Epic Epic x 8
    • Like / Agree Like / Agree x 7
    • List
    Last edited: Jun 4, 2021
  2. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    2,210
    Trophy Points:
    93
    Location:
    Chicago
    Big Digression into Headamp basics

    A big digression here to answer some questions about headamps, phono-preamps and loading of carts which I had to answer for myself at one point or another.

    These are basic questions and answers. If you already know how all this works skip to the next post for listening comparisons. If you find the answers too basic feel free to pontificate somewhere below but remember this is a primer, not a math symposium.

    What’s a headamp? Do I need one?

    In order to work properly your phono preamp needs an input voltage from the cartridge to be at or above a certain level, but different types of cartridges put out different levels of voltage. Consider the following cartridge types and their general output ranges, measured in millivolts:

    • Moving Magnet (MM)- 2.5mV to 5mV
    • High-output Moving Coil (HOMC)– 1.6 to ~2.5
    • Low Output Moving Coil (LOMC) - 0.15mV to 1.6mV

    Any phono preamp will work with carts in the moving magnet range of 2.5 to 5 mV. However many will not support moving coil carts since performing well with the lower input would increase the cost and complexity of the design and build.

    So, if you have a phono preamp that only supports the MM input range, how to use a MC cart? Place a device between the cartridge and the preamp that will perform a linear amplification of the signal. (Note that this amplification should be linear, as opposed to applying equalization such as a phono stage will.)

    The device you just inserted in the chain is a step-up transformer (SUT) or a headamp. While SUTs are passive transformers, headamps are active devices that allow you to variably adjust the loading needed to support moving coil cartridges while applying (hopefully) linear gain.

    The devices I’m testing here are all standalone headamps.​

    Why not just use a cartridge with a higher output?

    Moving coil cartridges are considered by many to perform better than moving magnet, with the low output creating a deeper and wider soundstage. Higher output cartridges are usually more forward-sounding. In the end it comes down to taste and convenience.
    Do all phono preamps require a separate headamp or SUT to use a moving-coil cartridge?

    No, some preamps will accept lower output cartridges directly. Often there are two sets of inputs, one for moving magnet and one for moving coil. More expensive preamps may have multiple settings to adjust load and gain, just like a separate headamp would. But even if your amp can support low output carts directly you could always use its moving magnet input settings with a separate headamp or SUT in front of it.​

    What’s load and how does it affect playback?

    Load is the cumulative electrical impedance, measured in Ohms, that the cartridge sees from the attached device (headamp, SUT, or preamp) and the cable attaching the two. Adjusting the load changes the sound coming out of the system. Too low of a load will choke out the signal and make music sound muddy and flat. Too much will lose the bass and make the signal thin and bright.​

    How does gain affect playback (beside the obvious)?

    Too little gain and you can’t increase the volume to the levels you prefer for playback. Too much gain will limit headroom, which can result in distortion and clipping when you turn up the volume. It will also give you a thinner, brighter presentation.​

    How do you determine the correct load for your cartridge?

    A range of loads can be ‘correct’ for your particular system, and the specific best value finally depends on your listening preference.

    Rule of thumb is that load should be, at minimum, 10-times the internal impedance of the cartridge. For example, the Ortofon cartridge I performed my tests with has an internal impedance of 5 Ohms. Rule of thumb would put the minimum load at 50 Ohms or above. Coincidentally, the manufacturer of this specific cart recommends using between 50 and 200 Ohms.

    Headamps often have pre-set loads you can choose from. For instance, the Muffsy lets you choose between 47, 60, 69, and 100 Ohms by default. In this case you’re a bit limited but you get to choose whichever’s the closest to the sound you like. Other headamps give you a vast range of values by using resistors or other devices in circuit. And don’t forget: You have to add in the impedance of the phono cable as well. High end cables often try to minimize their impedance for that reason.

    There are epic dissertations on the internet about determining your absolutely ‘correct’ number. You’ll be told the rule of thumb is garbage, that you should ignore manufacturers recommendations and reported internal impedances, and that you should use the author’s exotic mathematical divinations and theorems to find the value.

    My bottom line on the subject:
    • The rule of thumb works to determine your starting point for testing
    • You don’t hurt anything by testing various loads (but watch those high gains)
    • Ignore the math, do it by ear, find the load and gain that works best for you
    Why not just buy a SUT?

    A SUT is a passive step-up transformer which amplifies the signal based on the number of windings it contains (the step-up ratio). The load presented to the cartridge from a SUT is a function of the input impedance of your phono preamp , reflected through the number of windings in the transformer. Some SUTs have a High and Low impedance setting which can change that effective load by changing around their internal wiring.

    Common knowledge dictates a well-made, dialed-in SUT will outperform a headamp in any given system. “It’s a passive device that can’t introduce noise.” “It’s a long, lossless wire.” “It’s expensive as hell so it must be great”. Etc.

    So why not just buy a well made SUT and skip messing with these noisy, complicated, cheap ass headamps?

    1) You want to buy a SUT that presents the cartridge with your preferred, dialed in load. To figure that out you can:
    a. accept advice from a biased vendor who’s never heard your system and doesn’t know your sound preferences
    b. trust statements by random people on the internet who, again, don’t know shit about you
    c. guess
    d. do some testing with a headamp
    2) A SUT is inflexible for testing. It may allow you to switch between similar carts and cables but if you’re audio-curious or even just get restless you may be better off with an adjustable headamp.

    3) A well-made SUT can be expensive as hell.
    It’s not as bad as all that actually. Figuring out load and gain required isn’t an exact science and cartridges can sound good over a fairly wide range. That makes a good SUT somewhat flexible between similar cartridges. But if you plan to change cartridges or preamps, or you don’t have all the pieces of your dream system in place yet, a headamp (or an adjustable phono preamp) is more flexible, more convenient, and a better value proposition.

    And, my purpose in these listening tests wasn’t just to get to the end of the journey that fast, I wanted to see how a headamp worked and what they might be good for. The next couple of posts document that.
    BTW, if Ive mangled any of the questions or answers above id like to know, please post.
     
    • Like / Agree Like / Agree x 8
    • Epic Epic x 1
    • List
    Last edited: Jun 5, 2021
  3. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    2,210
    Trophy Points:
    93
    Location:
    Chicago
    Notes and Findings

    These are not presented in any particular order. Prices are as of the date of this post.

    Muffsy MC Head Amp Kit
    https://www.tindie.com/products/skrodahl/muffsy-mc-headamp-kit
    $170 for kit (shipped), including power supply and back panel
    $20 for the recommended enclosure
    $20 for Triad WAU160-750 16VAC 750mA wall wart
    ~ $15 for various additional materials and hardware replacement parts
    Total Outlay: ~ $230 USD

    [​IMG]

    Technical:
    You can buy a kit containing all the parts for the Headamp, the PSU, and the back panel for the suggest enclosure, for $170. (Or at least you could, it looks to be sold out). You buy the case and AC-AC wall wart separately.

    Input impedance: When you when you build you choose between 2 sets of switchable impedances:

    • 47, 60, 69, 100
    • 50, 75, 100, 300

    Once built, dip switches inside the box can be set to choose between your selected four values. The case isn’t made for continual opening and closing so it’s not adjustable on-the-fly.

    Gain is static 24.6 dB, the manufacture lists it as the following:
    • 0.15 mV input = 2.5 mV output
    • 0.3 mV input = 5 mV output
    • 0.5 mV input = 8.5 mV output

    The instructions give you an option to reduce the gain further by substituting resistors (not included with the kit) but I have no idea why you’d ever want to do that.

    Build:
    The provided boards are well made and uncrowded, using only through hole parts. Stuffing and soldering was easy enough. Instructions for the build and testing of the completed units were clear throughout. I rate the build as easy.

    [​IMG]

    The resistors and capacitors provided were cheap though. None were better than 10% tolerance and some were more than 20% off. I replaced a lot of them with tighter values for my build.

    Several unneeded pieces were included in the kit, including extra insulators for the RCA jacks. This led smart me to have to go back in and remove them to get the grounding to work properly. The instructions also require you to sand paint off the case to complete the grounding of the circuit. I added a little solder there to make sure the connection was solid.

    [​IMG]

    The completed unit is smart enough if a little sparse looking and lightweight. Given the small size of the unit the RCA jacks are a little tight but I had no issues.

    [​IMG]

    Summarizing the build on this, it’s a good and simple project but having some upgrades for the resistors on hand.

    Sound:
    • listened mainly at 47 and 60
    • At 47 Ohms nice bass
    • slightly pushed low mids compared to Piccolo, never gets muddy
    • High frequencies slightly recessed after about 6 k, less definition than Piccolo
    • Less edge, sharpness
    • Imaging just OK to good, slightly flatter presentation
    • Gain seemed low compared to manufacturer specs
    This is a capable little headamp that performs well. At roughly the same size and price as the Piccolo I find myself comparing the two. Its slightly warmer in the low mids than the Piccolo at the same 47 Ohm setting making it just a bit fuller without ever becoming muddy or bloated. The top end is slightly more recessed with less air and edginess. Not dark.

    Imaging not as the Piccolo but present and defined. Nothing jumped out at me, a solid if slightly flatter performance. Not as much clarity as the Piccolo.

    For some reason the gain was low compared to the other units, I had to boost gain on the phono stage where that was available. There was still plenty of listening room.

    Lounge Audio Copla https://www.loungeaudio.com/copla

    Standard version: $310
    Silver wiring version: $420

    [​IMG]
    The unit I used for testing has the silver wire upgrade.

    Technical:

    Uses a single knob for simultaneously control of gain and impedance. Allows from, at the low end, 40 Ohm and 27dB gain to, at the high end, 300 Ohm and 9dB gain.

    This uses LEDs and photo diodes for the gain/impedance control. A transparent bar at the top gets brighter or dimmer as you adjust the control. There’s a small balance control pot on the back of the unit, no doubt to combat the inherent variability of photocells. No other unit I tested had a balance control.

    There’s no indication of the specific load /gain at any point on the dial so its more ‘by ear’ than the other headamps. There’re also no detents in the control so if it gets bumped you’ll need to dial it back in by ear. I used tape to mark my preferred spot on the dial

    Power input is specified on the unit as 18VAC, 500 ma but Lounge audio provided a 16 VAC, 1 A unit they stated works just as well. I ended using a good Triad 18 VAC unit.

    Build:
    The fit and finish is nice. Lounge Audio also makes a phono preamp, the Copla is designed to match its appearance.

    The RCA jacks are too close together on the back and wouldn’t allow the bullet plugs on my RCA cables to connect. I had to use and extender jack on one of the cables to allow both to be connected. That’s a deal breaker.

    [​IMG]

    Sound:
    • Top end is rolled off
    • Notes seem rounded
    • Bad clarity \ definition
    • Recessed high mids ?
    • Flat imaging

    Performance on the other units were variations of degree so I’m hesitant to say which of them was best. I’m not hesitant to say this was the worst. The main issue was clarity and an inability to get good imaging no matter how I adjusted it. The top end seemed rolled off, there was a distinct lack of air and definition in tracks where it should have been. I suspect the high mids are recessed. Plenty of bass.

    Don’t know what else to say here. In a video on the product site the vendor talks about the white paper he designed the circuit around, it appears to me he was more interested in working with photo diodes than focusing on the sound.

    Interestingly the vendor has a video in which he expounds on tuning the impedance up or down to match the type of album you’re listening to (Classical, Pop, ‘Thrift store finds’.). Not a bad idea though it may strike those people trying to reach a specific performance point as unusual.
     
    • Like / Agree Like / Agree x 3
    • Epic Epic x 2
    • List
    Last edited: Jun 4, 2021
  4. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    2,210
    Trophy Points:
    93
    Location:
    Chicago
    Hagerman Audio Labs Piccolo2
    https://hagerman-audio-labs.myshopify.com/products/piccolo2-mc-preamp
    $259 USD

    [​IMG]

    Technical:
    “The active circuitry uses low noise matched discrete JFETs in a no-feedback gain and buffer configuration, offering very low noise and distortion. The sound is extremely neutral leaving no sonic signature.”

    Detented knobs on the top allow the following values to be selected separately:
    • Gain values: 0, 12, 20, 26 dB gain (1kHz)
    • Input Impedance (load) values: 47, 100, 220, 470, 1k, 47k ohm input

    [​IMG]

    Comes with a Meanwell GS06U-6P1J wall wart, 24 VDC 250mA

    Build:
    The unit has a low cost, almost DIY look with a see-through plastic case and cables going in one side and out the other of a 3 x 5 x 1 inch case. This isn’t audio jewelry for display.

    [​IMG]

    Knobs on the outside of the case make this the easiest, other than Copla, for on-the-fly adjustments and experimenting.

    The Gain and Input knobs on the top aren’t annotated, you have to look at a sticker on the underside to figure out which is which and where specific values are. With all the switching I was doing this led to me messing up settings occasionally as I transposed knobs and direction of rotations.

    Sound
    • Clear, clean. good imaging
    • Extended bass in all settings
    • Extended air
    • Not warm, less pushed in upper bass \ lower mids (100 to 400?) but not sucked out
    • Presented female vocals well (mezzo soprano) and forward
    • Less full than others, especially Musical Fidelity and Audio Design
    I listened to this mostly at 47 Ohms, sometimes at 100. At those settings this had the widest range and dynamics of all the units I listened to. Bass was present but not at all pushed, high frequencies were emphasized without going into sibilance or brassiness.

    This was less full than the other units, slightly less than Muffsy and a distinct departure from the Musical Fidelity or Audio Design. I really liked the sound, it brought imaging into sharp focus especially with live acoustic recordings or the female voice range.

    I’d summarize the sound as clean and sweet, which I happen to like a lot.

    Audio Design MCP-1
    Original price: ?
    Current price used: > $100

    [​IMG]

    This is from Audio Design, an apparently short lived and generically named Canadian company. It’s said to be a clone of the McIntosh MCP-1 http://www.roger-russell.com/mcp1.htm. I’d date its manufacture from ’85 to ’95 at the latest. The looks of the unit and the user manual written for engineers speaks to another time when technical performance was king and audiophiles were expected to know what the hell they were doing.

    This unit is a loaner from @k4star my thanks for the use. These seem scarce on the used market recently.

    Technical:
    Base input impedance is 470 Ohms but you add externally mounted load resistors to get to the exact value you want. This is easy as sockets are accessible directly on the back of the chassis. If you purchased this new you also got a selection of loose resistors to experiment with (Now we know the company owner was an engineer.) I found this method the most convenient for experimentation as long as you have a a selection of resistors lying around.

    [​IMG]

    Output gain is selectable at +20 or 30dB, the gain may change slightly depending on the value of the loading resistor you use.

    Power is a custom, unpolarized wall wart that connects to the unit via a DIN jack.

    [​IMG]

    This unit is maybe 35 years old at this time. I didn’t open it up to test components and I didn’t hook it up to a scope so it may not be performing as it did in its youth.

    Build
    The manufacturer states ‘Immunity to RF Interference”, which I believe. The case is a no nonsense, heavy ass steel box with a single LED on the front.

    There’s plenty of space on the back panel for all connections.

    Sound
    • Listened at 47, 56 and 68 ohms
    • Wide sound stage, not very deep
    • Plenty bass
    • Full middle, not muddy
    • Rolled off top end, little air

    The unit has more warmth and fullness than the modern units, leading me to wonder how much preferences have changed since the 80s and 90s. This was probably the fullest sound other than the Copla, but where Copla was just blurry this was always in control. Bigger bass than other units, maybe not as deep as Piccolo but more forward and prominent.

    This seemed significantly rolled off at the highest frequencies, with less pierce and air than anything but the Copla. However, mids, high mids and presence region were present and adequate. So even though it might have the narrowest frequency range from the units it did everything very well in between

    A bit more refined and clearer than the Musical Fidelity from the same era even while giving the bass a bit more presence.

    The unit seemed to respond to small changes in the resistance loading with big changes to the sound, given the extreme ease in changing out resistors I’d be interested in experimenting with higher values.
     
    • Like / Agree Like / Agree x 3
    • Epic Epic x 1
    • List
    Last edited: Jun 9, 2021 at 4:39 AM
  5. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    2,210
    Trophy Points:
    93
    Location:
    Chicago
    Musical Fidelity AC-1
    Original price: $550 in 1982
    Current Used price: $200 to $300

    [​IMG]

    This was a recommended as a good fit for the comparison so I found one on the bay. I made no changes or upgrades to the 30+ year old circuits so it may not be at its youthful best.

    Technical
    This one I can’t even find the manual for; Musical Fidelity doesn’t even list it in the archives.

    It appears be dual mono. There’s a set of internal sockets that allows you to insert your own resistors to adjust the impedance. Per internet this has 20dB of gain, the amount can shift with your choice of load resistors since these are running in parallel to the cartridge signal as a voltage divider.

    Note the two resistors in sockets at the top of this pic:

    [​IMG]

    Power is a permanently attached custom remote power transformer. There’s plenty of lamp cord between the transformer and the box, looks like they want you to keep it away to avoid hum. I had no issues with hum at all.

    Build
    The box is easy enough to open with just fingers as the bolts attaching the top have knurled knobs. Once open changing the loading impedance by switching out resistors is easy, though the nearby exposed wiring is a little close for my taste.

    During my last round of testing, after changing the loading resistors, the right channel stopped working. A sign of aging no doubt, will have to troubleshoot.

    The case is heavy steel with a plastic top.

    [​IMG]

    Sound
    • Listened at 47, 56, 68 Ohms
    • Flatter than Piccolo \ Muffsy (due to warmth?)
    • Not as much dynamics as MCP-1
    • Spacious

    This is a very good box with more warmth and fullness than the Piccolo or Muffsy. Not slow, everything was defined but not as edgy or precise as the modern units. This isn’t romantic tubes but a fuller sound that was pleasing both with sparse acoustic and jazz recordings as well as bass heavy pop stuff.

    I’m a sucker for an airy presentation but this did well without having a vastly extended top end. Imaging was wider but less deep than the Piccolo or Muffsy. Given the extreme flexibility in changing the input loading I’d like to do more experimentation with loads to see if what higher values might do here.

    Unfortunately, the right channel went out during the last shootout. I’ll probably go to the trouble of determining the issue, I’d like to hear more on this one.

    Music Reference RM-4
    Original price: ~ $800?
    Current Used price: $300 to $400

    [​IMG]

    This is the only tube step up I tested. It looks to have been manufactured in the late 80s. These were marketed multi-nationally and look to come up on the used market regularly. I got this one in fairly late in my listening, it only went through one shootout with the Nighthawk.

    Technical
    Uses plug-in proprietary modules for gain. It looks like you could choose your preferred gain when you placed an order. Mine is labeled 27dB, I’ve also seen images for 12, 21, and 30

    Uses a proprietary plug-in module for cart loading. A chip socket on the board accepts a reversible box labled 100 Ohms on one side and 300 Ohms on the other. I suspect if I open that box up I’ll find a resistor or capacitor that could be changed out.

    [​IMG]

    Sounded like ass for a good 45 minutes when I started it up. It uses two 6DJ8 tubes, I installed Telfunken EC88s

    Build
    Lightweight aluminum case with an anodized front piece.

    Looks small shop hand made with plenty of space on the board. A modders delight.

    The RCA jacks on the unit are fairly cheap and recessed into the case enough that my cables needed extenders to plug in. Time to re-terminate those cables?

    [​IMG]

    My unit came with rackmount wings and an external, front-mounted power switch in one of the wings. Looks like these were made to order for clients but in sufficient quantities as to allow options to be somewhat routinized.

    Sound
    • Used 100 Ohm load setting
    • High frequencies rolled off, some air but not much
    • Minimal but present bass bloom, pushes sub bass \ bass slightly higher than mids
    • More bass than other units
    • Good imaging, depth

    This was the only tube amp I tested and it has a distinct sound signature versus the rest of the units in this test. Bass bloom is ever so slight but present enough to make it instantly recognizable from the other units. (BTW, the term ‘bloom’ here is not meant to indicate a flabby, soggy bass section as members around here think its defined.)

    If you expect a headamp to be sonically transparent and exactly linear this isn’t it. Still, sounds great. Bass and sub bass are pushed slightly compared to the rest of the range, feeding this into my comparatively bass-light TC-750 it filled it out nicely. It may have been a bit too much feeding into the Shindo tube phono stage.

    Good imaging, not as sharp and defined as the Piccolo. Little air but a reasonable extension to maybe 10K. Overall the sound is softer than the SS units without becoming slow or ill defined. Tube listeners know what I mean here.
     
    • Like / Agree Like / Agree x 3
    • List
    Last edited: Jun 4, 2021
  6. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    2,210
    Trophy Points:
    93
    Location:
    Chicago
    Summary

    The units are all good, except the Copla which sucks ass.

    IMHO.

    Between the remaining current production units, the Piccolo2 at $260 seems a better value proposition than the Muffsy, which is about $230 + your time in building and testing the unit and - the warranty you get with the commercial product. Although if you feel the need to DIY by all means go for it.

    I also think the Piccolo2 outperforms the Muffsy by a good margin in clarity, range and ease of use. Muffsy while it performed well overall didn’t match the clarity and crispness of the Piccolo. It did exhibit more bass and mid range but I preferred the Piccolo’s better imaging and relative sparseness on most acoustic and jazz recordings I listened to.

    Among the older units I’d give the Audio Design MCP-1 the slight nod over the Musical Fidelity AC-1, especially as the latter is non-functional at the moment! When they were both working it was a close race and it was harder to point out any specific area that towered over the other unit. However the MCP 1 just felt a bit clearer than the AC-1, though both were noticeably warmer and fuller than the modern units.

    Finally, the Music Reference RM-4 would be my choice for feeding a solid state phono pre-amp with a dry presentation, say the TC-750. Tube refuseniks can dismiss this immediately for coloring the sound but I can see why the unit was popular back in the day. I suspect the purchase price was above my $500 mark originally so its probably not fair to throw it in this mix. With inflation that difference is probably even more exaggerated, so at the used price for this it might be a good purchase when it comes up if your OK doing capacitor refreshes.

    The prospect of that looming cap replacement for me and the failure of the AC-1 during testing is a good reminder to me that when you pursue vintage greatness you have to be ready to deal with troubleshooting and strife just to get a stable system going. With that in mind the Piccolo2 seems even more attractive as a good set and forget piece with easy tweaking options should you need them.

    One other thing to note: Headamps are by design adjustable, and the main adjustment you make (impedance) directly affects how flat, bassy, bright, or thin the sound becomes. So I'm aware that my observations of these amps is subject to these choices I've made and how Ive configured them. They may be absolutely great in your system, they might get better (or worse) if I keep messing with them here.
     
    • Like / Agree Like / Agree x 5
    • List
    Last edited: Jun 4, 2021
  7. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,219
    Trophy Points:
    113
    Location:
    Northwest France
    The reasoning I understood is that a coil is far lighter than a magnet. The reduced mass will track groves more accurately but the trade off is that you won't be able to generate as much current as a moving magnet. Thus lower output.
     
  8. ogodei

    ogodei Headphone Heaven Gatekeeper

    Friend
    Joined:
    Feb 9, 2016
    Likes Received:
    2,210
    Trophy Points:
    93
    Location:
    Chicago
    @Cspirou, as I understand it the better performance comes from the lower weight (mass) of the cartridge reducing the tracking inertia (drag) against the vinyl. Less mass and inertia allows the cartridge to track delicate changes better\faster. So, better tracking of very high-frequency content, improved transients, more detailed reproduction of the sound.

    In both types of cartridge the output signal is produced by a magnet and a coil of wire moving in relation to each other. In moving magnet, the magnet moves. In moving coil, the coil.

    I've seen two explanations of why the output from MC is lower:
    • The lower weight of the cartridge results in smaller movements between the coil and magnet. Smaller movement = smaller output
    • The coils in a MC cartridge are smaller than the coils in a MM cartridge. Smaller coil = smaller output

    I don't know enough to say if the latter statement is true. I do know the difference in output impedences between MM and MC is due to the difference in the coil size and composition.
     
  9. k4rstar

    k4rstar Done his time

    Friend BWC
    Joined:
    Jun 11, 2016
    Likes Received:
    5,454
    Trophy Points:
    113
    Location:
    Toronto, Canada
    an epic shootout! thank you for taking the time to write this up, it was an interesting read. the MCP-1 stacked up against the more modern players the way I expected, although I never listened to the thing before I sent it to you. Audio Design was based in Kitchener, ON just over an hour from where I live and I see their stuff on the used market every once in a while.

    for posterity, here's a link to the hard to find owner's manual: https://drive.google.com/file/d/1c4_oeqFc9Pfn_mLpwmTQZ5K7kYSLhXfb/view

    and a photo with the cover removed:
    [​IMG]
     
    • Like / Agree Like / Agree x 2
    • List

Share This Page