How to Pass a little time ...cont

Nice! I'm so behind on building the kits I have smh...

 

That's the beauty of DIY, sometimes I just go down to my workbench and bath in the possibilities

 

Hahahaha!

I decided that no matter what, Quasimodo is like 15 parts so I should find the time to at least get that done.

 

I was tempted to build one too, but have been using more SMPS supplies.

 

I am as well for the small stuff but for FW amps and Wolverine I'll be using trafos.

 

Do let us know what you think of the wolverine, was tempted but too much stuff already. The only one I am waiting for is the XA252 as that may replace the F4 (or I will rebuild sissy and get rid of the demons = one channel drifts a little, nothing crazy(70mV ish) but more than I would like)

 

Well I got on mousers case and had them send me the parts of my order they did have now... had to make another small order of mostly smd resistors, waste of shipping money ;( and I just dont have/can't seem to source 2 miniature relays in through hole form... I may have to just get some surface mount versions and solder them to the vias ;/

Also don't have the main transformers yet. Mounting holes are for R cores but it sure would be more convenient to source toroids ;/

But I have gotten this thing under way... semi pass related f5x preamp.

 

Very cool. Patrick's engineering is a masterpiece. Shoot me a dm with the relay part numbers, I have a bunch of random stuff.

 

My engineering on the other hand is a little questionable. I messed up measuring the cutout holes on this one, just aligned for the holes if it were backwards... still looks okay from the outside I suppose.




I would prefer I had tabs on my iec inlet so they would be covered by the connectors but these were what I had on hand for this sized cutout. Pretty sure I have some chassis mount fuse holders around here somewhere...

 

Getting really close... missing some smd caps because I had the BOM for an older revision of the main digital pcb and the schematic only covered part of it. Have to try and fit smd versions of the mute relays to the through hole vias. If that doesn't work I will leave sockets in and hope that I can fit the relays in at a later date without having to take the whole thing apart. It should work fine without them just no mute functionality.

Also gotta drill some holes to mount the toroids and do a bunch of testing before wiring up the amp chassis. PSU chassis is not so hard to work in even with all the walls and wires in place... amp chassis practically everything is nigh unreachable if the walls are in place ;/

 

A few people in DIYA have made mono ACA minis so I figured why not? This is a dual mono with Khozmo stepped attn. Biased pretty hot with the heatsinks ~59 C. Will need to turn it down a bit lol.

I have a vanilla Mini and if I ever get to it will build another dual mono with LPS and fancy parts. It's a fun and cheap way to compare what audible differences there are.

I'm about 10 minutes into listening to this thing with my cheapest (Eligia) cans in case of fireworks. The bass is ridiculous. Wow.

I'm using Vishay Mosfets but will swap them for Harris at some point.

 

an update to M2OPs

hacked together a "chassis" so that i could decide how much effort to put into it





after running it for several hours and it not killing my test rig, I decided to bring it up to the main rig and have been running it for that past few hours ( I had the day off - what better way to spend the free time )

it has a very big sound - oodles of power and control and just as much finesse as the F4. This might actually be the one that will end up being installed long term in my rig. Have I mentioned before that I hate case work ... I may just temporarily McGyver it to be petsafe and then if it is to stay , find the inspiration to make it pretty

a very easy one to build and sounds great

this one uses smps power supplies - FlatPac commercial units - each is a dual 28V supply, rigged up to dual rail and run through a filter / cap multiplier for clean power.

Input is XRK audio on Etsy - BTSB - an opamp based SE to BAL input board.

such fun ..dB

made a faceplate and stained the back espresso - was going to try steam punk but ended up with barndoor refinish look

M2ops by dufniall_dihardiyr, on Flickr

 

and because I built the balanced M2OPS power amp, I had to build a balanced preamp for it - the Iron Pre from DIYA



it sounds very good

 

How do you like the IP?

 

This is what I wrote over on DIYA when asked the same question

"I didn't know what to expect, my default preamp is actually designed as a dedicated headphone amplifier (SE) - it is a hybrid design with a tube ( SRPP like - really a grounded grid ) capacitor coupled to a mosfet current buffer - it is a beautiful piece of gear and I have been very happy with it. What I like most is the bass definition and authority as well as the level of detail retrieval. The sound is definitely coloured by the tube but it is not tubey - I think of it as a DHT-like sound without the crazy money of DHT. Now this means nothing as you will not have heard this to reference what it is I was coming from BUT what is relevant is that I did not experience any loss of those elements and ( perhaps new toy effect ) thought that there was a bit more all round - background seems "blacker" with more noticeable attributes of what I liked about my previous preamp = more definition around bass with good authority, no loss of micro or macrodetails, voices project into 3D space. A very enjoyable sound and retains that natural / organic aspect of music / instruments which keeps me listening.

I can compare to the B1 tube preamp = this to me had a very "warm" signature and overall it was too much honey for me.

My favourite feature with the Iron-Pre is no start or stop thump = completely silent ( not the case with my tubed pre which although has a relay to cut it, lets enough through for a lively thump )

Do I think it is worth building - yes, it is a keeper for me."

The previous pre is my Liquid Glass - I really loved the sound as did everyone who has listened to my system but this just seems "better". It could be the balanced nature front to back - it is not analytical but it is not warm goo either. There is depth and substance which is often lost in the audiophile quest but the tonal balance, detail retrieval etc is all there.

considering the "kit" is $150 = this is the 2 boards, the cinemag transformers, all the transistors as well as the little switch board for the relay input selector



I think this is incredible value - the additional bits probably cost about the same again without the panel mount XLRs and balanced pot or chassis , so maybe $500-600 depending on how crazy you go with some of these additional components.

It is easily endgame playback
..dB

 

Thanks. I was on the list for the first batch of kits but decided to save the money for now.

 

I was in for the first batch too. Decided to save the money for how, and hopefully let someone buy the kit that will put it together in the near future. I really need to finish some projects I already have going before starting anything new.

 

would love to see more pics... I can see possibly putting this on my list of things to try. I love the chassis...

 

diyaudio iron pre thread

If you meant the balanced preamp, you'd need to put your name on a waiting list right now.

The chassis was something dbel did, the kit is the pictures a few posts up.

 

This was the boards being tested.

The chassis was made from scrap bits and some paint. Sides are pieces are stair treads (oak), front and back is MDF. Base is a metal plate from a recycled CD player and top is just a steel perforated sheet. I made a shield from a transformer u-clamp. Original plan was to use the chassis that they are making for the project but it uses 2 stereo pots which was not my ideal for adjusting volume

a collage of the process :