James Transformers

[Shannon Parks]

I like my little 10 watters from Euphonia. Question: Can anyone else check the datecode on their tranny boxes? Mine say 94-10-6, which leads me to swag that these are 12 years old. I worry that the 'James' factory might be a warehouse of old transformers that will have no new supply coming down the pike once these are exhausted - ie bad for new designs like my GetSetGo. I guess I could email Euphonia, but thought I'd quiz my brethren first.

[EWBrown]

I'll check to see if I still have my James trannie boxes, knowing me, I never throw anything away, unless it smells bad...

edit:


Yes, I do still have them, the date shown is 92-11-4 Either November 4 1992 or April 11, 1992. Either way, they're definitely old...


/ed B in NH

[Shannon Parks]

I received this email from Keith Tan of Euphonia Audio today:

Shannon

I dropped by your web site briefly and saw a thread mentioning the "weird" date code used on James transformers.

I thought I'd take this chance to clarify things a bit.

James (the manufacturer) is a nationalist, devoted to R.O.C (Republic of China), a.k.a Taiwan. Since R.O.C was found in A.D. 1911, one would need to add 11 to 1992 to yield the correct date, i.e 2003

Hope this helps.

Regards
Keith

Very helpful info, Keith. Many thanks!

[EWBrown]

I recently inquired Keith at Euphonia, he is current out of 6115HS and will have "equivalent" 6113HS in April. I'm not sure if this just a part number change, or a new/different item.

Update 4/11/07: The 6112HS and 6113HS are now in stock.

I just ordered a pair of the 6113HSs.

http://euphoniaaudio.netfirms.com/ea/nf ... cts_id=142


/ed B in NH

[EWBrown]

I'll repost so it shows up as a new posting and not just an easily-missed update...

Update 4/11/07: The 6112HS and 6113HS are now in stock.

I just ordered a pair of the 6113HSs. (new replacement for 6115HS)


/ed B in NH

[Shannon Parks]

Yes, the 6113HS and 6115HS are the same thing (or almost identical). I think the '3' clues us to the 3.5k primary and the '5' clues us to the 5k primary - while both models have, err, both primaries. I think I do like having 3.5k and 5k versus the 6112HS model. Indeed, the Simple 2A3 designs used 5k outputs.

FWIW, with old stock tubes I get the best numbers (both power and distortion) at 3.5k. Sounds great on both taps. Will post all this data as soon as I tweak the Sovtek 6B4G bias.

[EWBrown]

IIRC (without looking at "TanK"s site, for the actual specs) the 611*HS series trannies also have an SG / UL tap, and the positiioning of that tap for optimal performance is the major difference. The 6115/6113 has 5 and 3.5K, the tap is 43% for 5K, and 50% for 3.5K, etc. The 6112 is 43% for 3.5K and 50% for 2.5K which doesn't meanything to a 6B4G Yellow_Light_Colorz_PDT_02


I originally used black finished 6115HSs (direct from Taiwan) with EL34s in UL mode, with no NFB, and the results were very gratifying. I hadn't really sussed out the subtleties of single point grounding back then, so that amp has a very low level AC ripple/hum , which only shows up on very efficient speakers. Someday, perhaps I may re-wire it to get rid of the residual hum.

If you're running true SET, then the UL tap's relative position is irrelevant. So the either 6112 or 6113HS would be applicable to the G*S*G design, as long as there is a 3.5K primary Z available.

/ed B in NH

[TerrySmith]

I got my James transformers today! Very nice!

Now all I need to order is the board parts, two 6B4G or 6A3 tubes, and maybe a power trannie. Yellow_Light_Colorz_PDT_06

[EWBrown]

I got my 6113s on Monday as well, that was very fast service!

The 6B4Gs arrived from The Tube Depot Tuesday (4/17), a day early from the tracking data ETA..

Now all I need to do is select a suitable chassis to mount it all on...



/ed B in NH

[TerrySmith]

What size hole do I need to punch under the James transformers?

[TomMcNally]

1 1/2" is perfect for the James 6113/6115

[gogzhad]

I have some James Transformers I got a long way back, and looked at the boxes - they are 6123HS. Anyone tried these? Looks like they'll work, but might be overkill for the GSG circuit.

Any thoughts?

[EWBrown]

The 6123s should work very well, as good if not a tad better than the 6113s. They're a bit beefier, designed for 300B service, so they should loaf along happily with 6B4Gs, 6A3s, 6C4Cs or 2A3s. Yellow_Light_Colorz_PDT_02

/ed B in NH

[Shannon Parks]

I plan to make a few mods to the Getsetgo board for another product, like removing the rectifier and using 1N5408s (or whatever the fast recovery version is) and putting another 6SL7 on there. It would be a 300B version for the Getsetgo. The upgraded trannies I would select would be those 6123s. Kind of excited about that. For just $200 more that the economical Getsetgo, you could have a 300B SET.

That said, I promise I'll be looking at the Edcors first! Yellow_Light_Colorz_PDT_06

[EWBrown]

I think there are uF5408s... Sounds like an interesting new project!

Powering the 5V 300B filaments with DC may take about an ohm's worth of dropping resistor(s), for each one.

go4it! Yellow_Light_Colorz_PDT_03

I just sent off to TD for a pair of COBTEK (Sovtek) 6A3s for the second unit Yellow_Light_Colorz_PDT_02 Yellow_Light_Colorz_PDT_03 Yellow_Light_Colorz_PDT_11

/ed B in NH