Just measured my output voltage, and it was slightly out of balance:

(which corresponds to R-channel having a very small weight)

L+ 100%

L- 110%

R+105%

R- 110%

(Switching input channels produces same result, so it wasnt the signal source)

What primarily controls the gain? EL34? K216?, ecc88?

you are doing a single ended input right??

unbalanced to balanced is never absolutely perfect

and the input tube matching side to side is the most important.

you are doing a single ended input right??

jep

unbalanced to balanced is never absolutely perfect

ok, i'll wait till my balanced DAC is finished ....

The 110% is with regards to voltage? That is still quite good, less than 1dB. Many pots are worse than that.

Gilmore's Corollary of Murphy's Law states that the counterfeit MOSFET from eBay which saved $5 will take $350 of hard-to-find parts with it.

Edited April 4, 201214 yr by Milosz

Have you experienced this aberration with your T2 build?

I lost at least a hundred dollars to counterfeit parts. Also, 2SC3675 is 6.97 per piece at bdent for 30 pieces right now. That's over 200 dollars for just that part, and more if you want spares to do repairs. It's getting harder and harder for people to build this thing nowadays.

IIRC the J79 (or K216) was the most expensive part when this thread was started a few years ago. Ironically it has not changed in price much.

We should have cleared out Sanyo's entire stock of 3675 when they were $.50 each instead of being 'practical' and only taking 50-100 each per person

Is Futurelec questionable for that part? $1.65 each...

http://www.futurlec.com/Transistors/2SC3675pr.shtml

LittleDiode is less than bdent... they are usually hideous on pricing, and have I heard fakes from them?

I've bought some a week ago. Will report back if the voltage breakdown checks out. I will say that their warehouse seem to be in Asia, so that might be a red flag.

Does anyone have a good source for the screws that go through the PCB into the XLR jacks? I'm using these on another build and would like the stability. I think they are M2.2 screws?

found some at Ebay. I have a few extras if anyone needs some.

Pictures of a recently serviced original SRM-T2 if anyone is interested:

http://hifido.co.jp/KWstax/G1/P0/A10/E/0-10/S0/C12-64548-38255-00/

I think I still have those made in the USSR tubes somewhere...

So lock up your daughters, and lock up your wife; the Icarium stock up has begun

A little update on the futurlec C3675 devices.

They were sent from bangkok, delivered by Deutsche Post, and invoiced from Australia. That's interesting.

http://i.imgur.com/AbRHB.jpg

okay... bent legs, like the ones I saw in my local hobby shop. Fair enough. Anyways, from left to right: utsource, futurlec, and bdent

http://i.imgur.com/PLmj1h.jpg

straighten out the leads. All of them look similar. The futurlec devices have similar letterings to the utsource devices.

Measured the Vbr and hFe using the handy measurement tool recommended by KG:

voltage breakdown:

utsource 1057V

futurlec 1252V

bdent 1117V

hFe:

utsource 46 @ 10uA(Ib)

futurlec 23 @ 10uA(Ib)

bdent 41 @ 10uA(Ib)

Hmm... So the hFe of the futurlec devices is a bit low. However, I am not testing at database conditions, so that might be the cause. Will have a curve tracer in 2 months time, I'll learn how to use it, and report back again.

Yes, interesting. Fake parts are real nuisance and trouble causer.

Have a look at this video clip

For those of us who don't have full facilities to check the parts including myself, can only hope that, even if all effort is put in to make sure that the build is good, can only pray that when the switch is flipped everything works. Also hopefully, it continues to work properly for a long time to come. I only have the vbr tester which is insufficient to check other important perimeters.

Edited April 11, 201214 yr by Victor Chew

Indeed. The hFE test was meant to be a quick test to weed out fakes. No guarantee for these to be genuine yet.

So I was blowing these 4A rat shack fuses (had no problem with a higher quality 4A fuse that I pulled from the BA) on a T2 (blubliss DIY), and decided to hook up the wattage meter just to see what was going on. The logger can only take data once every second, so I assume the "Max Amps" and "Max Wattage" mean the max recording during that one second interval. Hopefully this will be some use.

Edited April 22, 201214 yr by purrin

Gotta love the inrush current. I think I used 3.15AT fuses up here (230V) but that is probably overkill. Mikhail used 6.3A in the ES-1 but those transformers dim the lights.

so anyone doing another round of boards?

I was lucky enough to get a set of boards from lil knight. I have been trying to get all the orders ready for the hard to get parts for this amp. Right now bdent.com has all but the 2sk246gr. I found some on ebay but after reading through the thread am not sure whether they are real or fake.

A lot of the parts have gone way up in price and I understand that since most of these things are now obsolete. The current pricing from bdent is

2sa1486 $3.52

2sk216 $5.69

2sc3675 $7.12

2sc3381 $17.75

2sj79 $8.82

Are there better prices out there? If this is what I have to pay, okay. But if there are more reasonable prices out there I'm having a hard time finding them and knowing that the parts are real.

Thanks for any help guys.

Sent you a pm about 2sc3381 availability.

Thanks for the help Deepak.

I would also like to know if the 3675 parts from futurlec were ever confirmed to be real.

I was lucky enough to get a set of boards from lil knight. I have been trying to get all the orders ready for the hard to get parts for this amp. Right now bdent.com has all but the 2sk246gr. I found some on ebay but after reading through the thread am not sure whether they are real or fake.

A lot of the parts have gone way up in price and I understand that since most of these things are now obsolete. The current pricing from bdent is

2sa1486 $3.52

2sk216 $5.69

2sc3675 $7.12

2sc3381 $17.75

2sj79 $8.82

Are there better prices out there? If this is what I have to pay, okay. But if there are more reasonable prices out there I'm having a hard time finding them and knowing that the parts are real.

Thanks for any help guys.

i can get way better pricing (at least, a year ago when i last ordered) on 2sk216/2sj79 but i'd be looking at ordering about 1,000 of each