[Dave_M]

I am planing to have a go at building a dynalo but am having some trouble sourcing parts in the UK. Only the 2SC1815 is available from farnell.. it also says "Available until stocks are exhausted" which made me think that parts listed in the Headwize artical are just out of date and have been replaced with an almost identical part.

So is there any known alternatives to the transistors (and FETs) used in the dynalo? What does one look for in a good trasistor? I wouldn't know where to start.

Would changing the transistors in the dynalo change how the amp sounds in the same way that swapping op-amps in other headphone amps would alter the sound?

 

[steinchen]

due to the bce pinout of 2sc1815 and 2sa1015 finding a replacement will be difficult (2n5088, BC550, 2n2222, 2n3094, ... won't fit). I built one Dynalo with 2sd667 and 2sb647 transistors but I don't expect them to be easier sourceable.

I ordered some 2sc1815/2sa1015 not long ago and had no prob sourcing them here in Germany, I still have some spare, just pm me if you need me to help you out.

Replacing / sourcing 2sk389/2sj109 is much more difficult. I recommend to contact dgardner, he has stocked quite some of them for supplying Dynalo builders. They could be replaced by 2* 2sk170/2sj74 but again they got a totally different pinout.

 

[Clutz]

Check out Ebay. That's where I bought mine. I only bought 50 of each, I sort of wish I had've bought 100 of each now - cause I had a hard time matching them as well as I wanted. In the end, I managed to get it so that it has 0mV of offset once the servo has kicked in, and I was able to get identical matches for the most important cases - but it wasn't ideal.

Cheers,
Clutz

 

[Garbz]

Hmmm my local supplier hasn't heard anything. Maybe just farnell aren't stocking the item because the only people buying it are dynalo builders

On headwize I seem to recall someone building a dynalo completely with different transistors. If you're willing to get creative then steinchen's limitation isn't a worry unless you go for TO220 transistors. I've managed to foul up a few PCBs in the past by putting the wrong pinout in, but using a shapie knife and some creative bending the transistors fitted.

 

[Dave_M]

Ah I forgot to mention.. wasn't going to bother with a PCB just build it on protoboard stuff

So the transistors dont have to be direct drop in replacements.

I've been doing some digging around on the net. I'm pretty sure all the toshiba parts used in this amp are now discontinued. And there is a replacement for the 2SK389 - the Linear Systems LSK389 if thats of interest to anyone.

I found CPC sell both transistors and the 2SK389 FET hurrah! But not the 2SJ109

I found somewhere else that sells the 2SJ109... but for £8 each! the 2SK389 costs £1.34 from CPC.

So, i just really need an alternative to the 2SJ109 now. It can be replaced with 2 individual FETs? Will they need to be matched aswell?

 

[guzzler]

Try cricklewood electronics

www.cricklewoodelectronics.co.uk

 

[Dave_M]

Quote:

Originally Posted by guzzler Try cricklewood electronics

Yeah thats where I found the 2SJ109 for £8. Dont think I am prepared to pay that much.

Does anyone know if 2N5462 is any good? They only cost £0.38
http://uk.farnell.com/jsp/endecaSear...=1017645&N=401

I couldn't find 2sk170/2sj74

 

[Tsappis]

I should be able to get 2SJ109, 2SK389, 2SA1015 and 2SC1815 at reasonable prices: 3.44e, 2.60e, 0.32e and 0.32e accordingly. Posting to the GB is only a couple of euros so if someone is interested I can call my supplier if they have them in stock. They should have though.

 

[Clutz]

Quote:

Originally Posted by Tsappis I should be able to get 2SJ109, 2SK389, 2SA1015 and 2SC1815 at reasonable prices: 3.44e, 2.60e, 0.32e and 0.32e accordingly. Posting to the GB is only a couple of euros so if someone is interested I can call my supplier if they have them in stock. They should have though.

I would be very interested - cause I would be interested in putting together my second dynalo!

Thanks dude!