Group Buy: MOVED TO NEW THREAD

whubbard · « **Reply #60 on:** 23 Jun 2008, 03:09 am »

Ron,

How did the testing go this weekend?

Is it worth putting some BC560s into the group buy?

-West

RonR · « **Reply #61 on:** 23 Jun 2008, 11:53 pm »

Hi West,

Testing of the BC560 was encouraging, I replaced T4 in the GK1 with BC560C, doing before and after tests by listening with my ear to the tweeters with the GK1 at full volume and the inputs shorted. There was definitely less noise with the BC560. Listening to music though, I was hard pressed to tell the difference. Maybe there was a smidgen more fine detail and spatial clues, but I might have been deluding myself!

Next step is to replace T6 (not sure if this will have any effect at all, but might as well do it), then if I can make up some matched pairs, T1 and T2.

BTW, the Sonicap 20uF Gen1 I was testing at C4 did work out to be marginally better than the 20uF Solen, though there wasn't much in it. Though the bass from the Solen was "Punchy", the Sonicap had less punch but was a touch more tuneful. Can't wait for the AudioCaps to arrive!

Cheers,

Ron.

AKSA · « **Reply #62 on:** 24 Jun 2008, 03:02 am »

Thanks for sharing this mod, Ron,

I would not expect a 560C to affect T6 either, as it's simply a power supply regulator, not strictly in the signal path, but well served by a 557 where beta is not important.

T1 and T2 could well be a different matter, however. A 560C would offer marginally lower noise and much more beta; this could be beneficial as long as they are matched on beta to within 1%.

Cheers,

Hugh

whubbard · « **Reply #63 on:** 24 Jun 2008, 04:02 am »

Ron,

I look forward to your results with the audiocaps as well. As of now I am thinking the group buy will probably be the sonicrafts as you did notice improvement in C4 and we will get a better discount if we just go ahead and use it at C7 as well.

I think I will also add in the BC560, 6 for each board. Someone will just have to explain how I match them and I will do it. Its not that big of a cost anyways.

-West

dayneger · « **Reply #64 on:** 24 Jun 2008, 06:59 am »

I think I'm going to take the bait as well! I'm in for whichever combination of caps and transistors sounds the best to our testers, IF someone can tell me quite precisely exactly what I'm supposed to do with them. It's been a while since I cracked the hood of my GK-1R and my documentation is buried somewhere in a huge pile of boxes. . .

Cheers!

Dayne

kyrill · « **Reply #65 on:** 24 Jun 2008, 09:23 am »

i agree but i think we will have to wait for Ron's audiocaps
but including the transistors ( can they be bought in matched pairs?)

whubbard · « **Reply #66 on:** 24 Jun 2008, 11:37 am »

looks like I'll be setting this up:
http://sound.westhost.com/transistor-matching.htm

-West

kyrill · « **Reply #67 on:** 24 Jun 2008, 12:18 pm »

O-o what an extra work ( for me)
i am willing for some extra to delegate this matching to
a (younger?) (more DIY engineer) kind of person

AKSA · « **Reply #68 on:** 24 Jun 2008, 12:47 pm »

Hey Guys,

This is easy.......

Buy 10 of these transistors, BC560C.

Then measure all the betas on a simple DMM, put them into batches of like beta.

You will get around two matched pairs from 10 devices.

Not too difficult; today I matched a couple of 557s; one was beta 409, the other 411. Took about a minute.

Cheers,

Hugh

kyrill · « **Reply #69 on:** 24 Jun 2008, 07:59 pm »

relief relief

i have a not so simple dmm but what is a beta, except it comes after alfa
and stops, dies before omega?

AKSA · « **Reply #70 on:** 24 Jun 2008, 10:50 pm »

Hi Kyrill,

Ah, beta is DC current gain, intimately related to AC gain.

Symbol is not the Greek beta, which you would expect (engineers generally are not classically educated!), but rather Hfe.

It is the ratio of collector current to base current (sometimes called bias). The ratio changes as the operational parameters of the transistor are changed, particularly collector current and temperature. These are the non-linear parameters within which a good design must operate. Most of these non-linearities are flattened out with negative feedback, and they need to be, because transistors are VERY non-linear.

The first transistor in 1948 in Philadelphia had a gain of three.

A high voltage, high current transistor like the outputs on the AKSA/Lifeforce/Soraya has a gain around 80. The BC560C should have a gain around the 450 mark. You can see how far we've come in sixty years!

Cheers,

Hugh

whubbard · « **Reply #71 on:** 25 Jun 2008, 03:56 am »

Kyrill,

Unless you really really want to I think it would be easier if I just included this in the group buy with the caps and sent them out myself. I feel like everyone going for the caps probably won't mind getting some match transistors either.

I was thinking of getting 2,000 http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=BC560CTATB-ND which will only cost $50 to be split among us all. Then we can all get ones matched at exactly 450. It will also add nothing to the shipping people will already be paying for the caps.

Hugh,

Is the 450 mark for all the BC560C (T1, T2, and T3) or just for T4?

-West

AKSA · « **Reply #72 on:** 25 Jun 2008, 04:25 am »

Hi West,

This is very nice of you.....

Yes, anywhere from 200 to 500 is just fine for the matched pair, but there is no advantage to using this very high gain device in position T6, which is merely a regulator device for the power rail.

Many transistors are sold in gain groupings; A is generally lowest, and C highest.

Sent off a package to you yesterday with a few silver micas in it, I'm sorry for delays, should have it midway through next week.....

Cheers,

Hugh

kyrill · « **Reply #73 on:** 25 Jun 2008, 08:22 am »

nice West, thx
by the way silver mica's: "The RelCap RTE is superior to small Silver micas and other small Polystyrene film and foils. The RTE is constructed from Polystyrene film and Tin foil. The sound is detailed and sweet. Tolerance is better than 5%."
picked that up in http://soniccraft.com/relcap_rte_capacitors.htm

gerado · « **Reply #74 on:** 25 Jun 2008, 10:52 am »

How about a group buy for this innovative innovation, especially for all you wood lovers!

got this from another forum

http://gadgets.boingboing.net/2008/06/24/boing-boing-gadgets.html

only if we could get the teleport to work will save more on postage.

just for a moment

LM · « **Reply #75 on:** 25 Jun 2008, 09:44 pm »

Hi Theo,

The 'finest extra virgin' really got to me. aa

Seriously though, I think you’ve discovered a medical breakthough. “……Microvibrations cause incontegrity, demodulative leaching and, ultimately, pixel flutter. Bad vibrations! Bad! Trust the brain/eye convergence that you'll experience with…..” So too much bad TV will cause letching (whoops I mean leaching). I’m still struggling with incontegrity though. Is that a medical term for visual incontinence?

Hell, I'm going to miss out on this opportunity as I already have my Solens!

AKSA · « **Reply #76 on:** 25 Jun 2008, 10:41 pm »

Any product which destroys the incontegrity of my PC, as well as disturbing the computational Feng Shui of my intersphere gets my vote every time.

I'm very impressed with this timely product; it surely hits a marketing niche with panache!

Hugh

RonR · « **Reply #77 on:** 26 Jun 2008, 09:59 am »

Methinks I'll be busy tonight!

The postman brought me 4 AudioCaps and a 10K TKD stepped attenuator this morning.

Cheers,

Ron.

LM · « **Reply #78 on:** 26 Jun 2008, 11:24 pm »

Way to go Ron but perhaps, unlike me, you will fit them separately.

You may then be able to tell others about which component brings what changes. All I know is that the combo of Solens (regardless of whether it’s the ultimate Cap or not) and TKD gives a large and very sweet upgrade.

whubbard · « **Reply #79 on:** 27 Jun 2008, 05:13 am »

Ron,
Hopefully you will be able to do the caps first so that we can see how they compare to the Solens and Sonicaps.

Also, did you get the vishays?

-West