i'm on a roll... the kgsshv

[kevin gilmore]

For latest version of kgsshv PSU, what value is the current limit set to?

about 90ma

[JoaMat]

Thanks,

Is it possible to increase that value? My intention is to get about 200 mA.

[kevin gilmore]

change the 15 ohm resistors to 5 ohms. But really that is a lot of extra heat

in the power supply.

or remove the current limit entirely by removing Q9,Q10,Q13,Q14

Edited October 16, 2012 by kevin gilmore

[JoaMat]

thanks for advise.

[gustavo.skn]

I'm currently buying the componentes for the kgsshv using the BOM by ujamerstand, but I have a problem:

2SC2705 4 Toshiba Mouser 757-2SC2705-O(TE6,F

2SC1815 2 Toshiba Mouser 2SC1815GRTE2FT

Bridge 1 STM Electronics mouser 512-KBU4M

2n3904 4 On Semiconductor mouser 863-2N3904G

These parts are listed as obsolete in mouser. I could find a replacement for the 2n3904 with the same specs (2n4401) , but got no luck with the other ones... Anyone have these and want to sell me? Or can help me finding a replacement that is ok?

Thanks guys

[Remolon]

For the 2sc1815, why not use ksc1815?, I made a Dynalo using ksa1015 and ksc1815, even in place of the jFet, and it works and sounds very well.

[RudeWolf]

I'm pretty sure that Dynalo can work with almost any sand you can get your hands on. I'm quietly plotting to swap the output bipolars on mine to BC550/560.

[jwzhan]

bdent has 2SC1815 and 2SC2705 in stock.

as for the bridge, KBU4M is just out. You can probably replace it with ones with higher current.

[spritzer]

More current in the bridge isn't a problem.

[livewire]

Ebay?

Sands not that rare, a bunch for sale over there.

Could be fakes, though at these low prices I doubt it. Bdent is one of the most reliable sellers but can be rather pricey.

As for the bridge, most anything will work if it has the correct voltage and current specs. (or a bit higher)

Pay attention to lead spacing as well. Works for me!

[Remolon]

Me too, I have another Dynalo with BC550/560 but not because I think that the Dynalo accepts everything but because of the similitude of the BJTs.

BTW, Could the BC550 be a substitute for the 2SC1815?

[RudeWolf]

Are 2SC1815 that rare? I have 50 pairs together with 2SA1015.

If I remember correctly the BC550/560 has about 4dB lower noise floor than 1815/1015 BJTs. That's why I would like to swap'em out. Any audible difference on your 550/560 Dynalo, Remolon?

[Remolon]

But how many are needed to obtain eight matched quad?

It is not a fair comparison, the two Dynalo have different setup: both have two mono PCB for audio but the one with ksa1015/ksc1815 has a power supply for each channel with separated grounds and a four pins DIN headphone output; and the other is a conventional setup, one PSU and a 3-ways output jack with a common ground.

[eggil]

bdent has 2SC1815 and 2SC2705 in stock.

as for the bridge, KBU4M is just out. You can probably replace it with ones with higher current.

Would this one work?

http://www.jameco.com/1/1/5263-kbu4m-e4-51-4a-1000v-silicon-bridge-rectifier-diode.html

[jwzhan]

Would this one work?

http://www.jameco.co...fier-diode.html

It certainly works... but it's back-ordered for 10 weeks from the date of the order. I'd just get a bridge with higher current (KBU6M, KUB8M) instead of waiting for 10 weeks.

[eggil]

PM ME If you need one or 2

[johnwmclean]

^ Nice one eggil

An observation after changing the output current to 8.8mA.

Whilst the balance remains stable, offset drifts around considerably.

I can achieve zero offset on both channels no problem, but it will drift ~5V or so over time.

Is ambient temperature a factor? I know 5V is nothing, but should I be worried about stability?

Edited November 1, 2012 by johnwmclean

[spritzer]

Larger thermal drifts should be the cause here and that's nothing to worry about.

[johnwmclean]

That makes sense then. Thanks Birgir.

[justin]

yesterday, i was on a Chinese parts sourcing website and saw several companies that claim to have 2SA1968. I sent in quote requests to 2 companies. This morning, I had 63 quotes in my inbox -- prices seem to range from $0.10 to $1 each. I have no idea if any of this is legitimate or how many parts are really out there.

Then I got a call from a company in Florida offering a quote -- who i suspect is Dalbani under another name. They emailed me, its like $10/each. Usually I am nice but i basically told them to fuck off. Now to see if any of these Chinese parts are real...

ok people, stop calling me...60+ quotes was enough

Edited November 9, 2012 by justin

[kevin gilmore]

see if you can buy 2sk389/2sj109 or the singles versions...

i'll bet you get a few hundred quotes.

[luvdunhill]

Do what Kevin suggest. Then use that list to eliminate from the other list. Profit.

[justin]

LOL i hate you China

this morning i get a call from a woman in China to quote the 2SA1968. she then emails me the quote -- Amy from HongKong Kemei Electronic Co.

tonight, 13 hours later, she calls again asking if i need a quote on 2SA1968. she has no recollection of talking to me. emails me a quote -- Evelyn from Dedicate Electronics Limited

both prices the same.

edit: actually the first quote was $0.26 and the next was $0.21

Edited November 10, 2012 by justin

[HeadphoneAddict]

Maybe Evelyn didn't remember you because she isn't Amy?

[justin]

called me from the same phone #, same voice. i asked her about it in an email, and she said something about "not being logged into MSN" or some crap. ok, guess when youre in hotmail you're Amy from one company, when you're in MSN you're Evelyn from another company with a different price. 75 quotes and theres probably 2 actual companies behind them.