Oh Sh#7! Eddie Current Studio B

@purr1n I'm not sure if you would know this answer or not -- can I convert my Studio Jr power supply to run off 230V power instead of 115V?

Moving out of the US soon. The Eddie Current website FAQ mentions being able to convert, and even having a local electronics repair shop do this (rather than shipping it to Craig). I emailed Craig a few weeks back and never heard back. I ended up dropping the amp off at a local shop, but they are saying the power transformer only has 3 wires for the voltages, rather than expected 4 wires to convert between voltages.

 

@wenbinbin2010 not sure how to convert the unit itself, but a cursory Google search shows there are external step down transformers you could use that aren't terribly expensive. Might be a better option than a complete rewire unless you are permanently moving out of the US.

 

That is the option I had planned for originally (and still the route I will go if rewiring is too complicated).

I transitioned my whole chain to components that can switch between US 120V and international 220-240V, as I do expect to be moving back at some point. I did buy a beefy step down transformer that can take up to 2400 watts, but it seemed more streamlined to do without the step down transformer if possible.

 

It seems that with only three wires you would be looking at replacing the power transformer, if you could find one with the correct spec's.

 

question on Studio B... I want to connect a sub (haven't purchased yet) to the lineouts, but want to confirm that the lineouts are disabled when I switch to headphones. The last thing I want is to have to crawl around to switch the sub off (or unplug the lineouts) everytime I want to listen to headphones.

TIA

 

On my Studio B the line outs are always active independent of the speaker / headphones selector switch.

 

Appreciate the answer... even though I don't like the answer

I suppose I can simply put a switch box between the amp and sub and use it to switch the sub off... Not to derail the subject too much, but anyone had recommendation for a decent RCA switchbox?

 

Ooo cool, did you long expose a shot of the Western Electrics there?

 

I just found the image on my phone, I can't remember which tubes they are but I thought you Studio B heads would enjoy!

 

Anyone used a 5U4/anything else other than a 5AR4 in Studio B? Got a good price on a supposedly NOS-ish testing JAN RCA 5R4GY (45 bucks - they’ve been going for triple that sometimes) on fleaBay after noticing someone on HF selling their Studio B with a Genalex 5Y3G and chatting with them about it via DM. He was saying it really helped tube-ify the overall sound, better than a driver tube swap, and I’m trying to dial things back in that direction some now that I have the neutral Elrogs as 300B’s. Doesn’t seem like many rectifier rolling impressions out there with SB, although that’s understandable given there’s probably less than 100 amps in the wild. Up until now I’ve been running a Mullard Fat Base GZ34.

Anyway, regardless I’ll report back what I think once it’s here to help other SJ/SB owners who might want to triangulate.

 

I have quite a few 5U4's, but have never tried them in the SB since they aren't listed in the manual (only 5AR4, 5Y23 & 5R4).

I know the 5U4 can be used in some amps (eg., in my Mogwai), but never wanted to risk them in the SB and I could never seem to find a definitive answer online.
----edit----
typo

 

I have been running a Philips 5R4GYS for the last few weeks. I found a copy of the manual at one point and it noted that 5AR4 and 5R4 tubes were ok to use in the amp. I haven't had a chance to listen in any detail, so no impressions at this point.

 

Little outside the lines data point, but somewhere along the way I read 5R4GY was also suitable in EC Af, so I spent some time with a coke bottle brown base RCA 5R4GY in mine. It loosens up the bass and smooths everything out in a way that makes the amp sound like it's half as powerful while still playing plenty loud. It's still decently punchy, so not quite whiffle-ball bat and down pillow dynamics, but it didn't suit the amp very well, imho. I guess a 5R4GY could be useful with certain upstream gear pairings, but might be a bit heavy handed, i.e., too much of a not great thing/sins of commission.

 

Yeah, I flubbed there - meant to say 5R4, sorry. I do figure given the 5AR4 has some of the lowest voltage drop of any rectifier (other than solid state rectification obviously), most of the alternatives are going to sound similar from the higher drop, since how that effects the amp circuit is what you’re hearing when you change to another tube, basically. Just my layman’s understanding though.

Anyway thanks for the responses, about what I expected re: smooth and diffuse from trying to read between the lines of other impressions of the RCA brown bases. The Elrogs are weird enough in their sounding non-300Bish and extended that I don’t think I’d consider something softish/smooth to pair with any other 300B, just doesn’t align with my sonic priorities or what I like about the amp, so I’m skeptical but only one way to find out. I’ll let the thread know what I hear.

 

The Mullard f32 (with the 4 notches) are no doubt excellent tubes but I find them a little surgical. I prefer the f33 rectifiers (usually marked Siemens/Amperex/Philips) like the one in the attached picture. They’re not cheap anymore but I’d recommend trying one if you can get a good deal (please don’t pay 200 crazy prices)

 

Once I went mullard f32 I've never wanted to look back. It was a bit startling to see that much difference with just a rectifier change. I do have an RCA 5U4 I'm probably never going to use if anyone wants it.

 

Okay, I actually quite like this what this JAN RCA 5R4GY brings to Studio B, but I’m pretty positive it wouldn’t play well in all configurations.

I don’t hear less power, it’s actually a smidge more gain-y than with the f31 Blackburn Fat Base Mullard I was using, if anything. I also don’t hear much rolling off of grit or high frequency etch/extension, maybe less than a few percentage points or so if I had to try and quantify. The biggest difference is tonal - notes are denser and heavier than with the Mullard and have more sweetness and bloom/toobiness. This sacrifices a tiny bit of delineation/separation, and just the smallest bit of air. Bass is definitely looser.

None of this is much of problem and is instead a boon precisely because of what I was getting at with thinking it may not work in all systems - my config had gotten a little too washed out and tonally anemic, even for me, with the Elrogs, a Bendix 2c51, and a Mullard GZ34, all while being fed by Yggdrasil GS and going into HD800. Great detail but the Studio B’s dryness was just getting cranked to 11 when I dropped in the Elrogs. I will say the Elrogs’ transparency reveals tube rolls with the driver tube or the rectifier that much more clearly since it has so little 300B syrup (relatively) to obfuscate or murk with. I have been using some GE 5670’s as the driver tube before the rectifier got here and that really helped beef up the sound too vs the Bendix. Now that the 5R4GY is in, it’s a toss up, the Bendix’s detail/delineation plays pretty well for my preferences again, but a GE 5 Star has a nice creaminess coupled with a little pleasant rasp on some tracks and more drive overall. In any case, it frees up more options now that the Mullard isn’t contributing to the dryness/thinness as it appeared to be once the Elrogs were in the picture.

Anyway, YMMV - could be too much thick toobiness with another headphone or source, or even just with a more classic 300B than the Elrogs. I’m running the JAN version of the RCA brown base coke bottle 5R4GY, but Andy at Vintage Tube Services (upstanding guy who tests his stock of tubes much more rigorously than the fleaBay dudes and sells them for less usually) has non-JAN brown bottles for sale at the link if you’re curious to try one out. I promise I have no affiliation:

https://vintagetubeservices.com/product/5r4gy-rca-rectifier-white-box/