Great new seller of Soviet Germs.

[Geiri]

I ordered some stuff from this guy. Top notch service and arrived quickly. eBay overcharged on shipping so the guy asked what I'd like to get for the difference and I had him surprise me.

[IvIark]

Yes I got my 10K and 100K trimmers today so it only took a few days to get here.  Also got some SFD112 germanium diodes which are still in the sealed Tungsram packaging.  Bargain at £3 for 50

[dbat69]

My order arrived with various bits thrown in for free including some (what look like) Ge diodes (two yellow stripes) - not sure what they are.
I tested the MP38s and was a little disappointed with the results, most of them in the 40-60 range and only 13 in the 60-65s.  I guess that is the luck of the draw although to be fair, the description did say they were only 25 to 55 hfe.

I would still say that he is probably one of the (if not THE) best seller I have dealt with on Ebay.  I am sure to be getting more stuff from him - thanks again for the heads up  

[Beaker]

When I tested these, my multimeter was playing up. All the readings I got of over 100 HFE appear to be errors, and almost all of these transistors actually read around 58 - 70 HFE.

On the bright side they sound absolutely amazing when used in the GE Fuzzrite layout, so I'm still a happy bunny.

[IvIark]

I wouldn't be too unhappy with that sort of gain range.  You'd be surprised at how good these sound in our usual fuzz circuits.  I don't know who it is who first said a Fuzz Face needs 80 and 120 hfe, but it's nonsense as far as I'm concerned.

[rocket88]

i totally agree mark. but i remember hearing/reading somewhere about the russians that the gain may not be what we are getting the readings as. that they may be higher then what we get when we test them. i completely forget the reasoning, but remember chromesphere over at DIYSB that was really looking into it because he was really pissed that he was getting low readings on some that should have been higher.

[IvIark]

Some of them have an internal resistor between base and emitter which will give inaccurate gain readings, I've got some GT313's which have this.  But I just think there is more to the quality of fuzz than simply the gain of the individual transistors, maybe another characteristic of the transistor is important too.

Obviously something too low or too high will be an issue, but I do think we have a pretty wide band of gain levels that sound great.

[dbat69]

I think it was Chromosphere who made the comments about the test hfe not being quite reflective of the actual when in use.  I recall this was due to the current/voltage being much lower in the test and he said to check against the curve on the performance specs.  The test is at a much lower level than the 'in use' result for Russian transistors.
I think that was my bad memory's recollection of the explanation

[rocket88]

Agreed. That's whatni remembered. He also made the comment about the importance of frequency response on the transistor, and the need to pay attention to that in addition to the hfe.

[tjdracz]

dbat69 wrote

I think it was Chromosphere who made the comments about the test hfe not being quite reflective of the actual when in use.  I recall this was due to the current/voltage being much lower in the test and he said to check against the curve on the performance specs.  The test is at a much lower level than the 'in use' result for Russian transistors.
I think that was my bad memory's recollection of the explanation

Our stompboxes use quite low currents. When you test transistors with something like Peak Atlas, you're also putting small current through the transistor so the gain reading will be close to what it actually gives in stompbox circuit.
Now with Russians, their gains are given at something like 25-40mA current. Now compare it with something like Fuzz Face that gets maybe 1mA at transistor base. With such a low current, the transistor is 'starved' and its gain is quite far from the datasheet figure (measured at higher current). Still, most of the time, it will work, as long as the gain is not TOO low, it should be good. Sure, you won't hit the magic  mojo numbers but the results are often better than expected, as Chromesphere videos show.

[inefficiency]

I just hopped on the train with these. I got a box of MP38 and a box of MP20A.

I can see that the MP38s are pretty popular. Anyone got any thoughts on the MP20As? I figured seeing as the MP38s are NPN, I'd get some PNPs as well.

The Hfe for them is 50-150.

[tjdracz]

MP20 are quite good. I';ve got higher HFE version (MP20D) and they behave fabulously. As you would expect with russians, hfe's are going to be lower than datasheet say but they still sound nice

[inefficiency]

Nice! Glad I grabbed them. I should have got some of those diodes Mark mentioned while I was at it, but maybe next time...

Slightly off topic, but whats the consensus on all these Hong Kong based sellers selling diodes and transistors? 99p for 10 or 20 germanium diodes and such? Are they garbage or worth a shot?

Got a couple of links for "mojo" parts here. let me know what you fellas think!

http://stores.ebay.co.uk/Paradise-of-Hi-end-audio-components?_rdc=1

http://stores.ebay.co.uk/Kriss-Elektronik?_trksid=p2047675.l2563

[tjdracz]

What transistors and diodes? With silicon it's always give. Germanium... don't know. Things like 1N60 that you buy and turn out to be zeners. What types are you taking about?

[inefficiency]

Let's see. Things like this;

http://www.ebay.co.uk/itm/1N60P-Germanium-Detector-Diode-FM-AM-TV-Radio-Detection-60-Pcs-/291059595034?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item43c480f71a

or these;

http://www.ebay.co.uk/itm/261375554771?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

[tjdracz]

inefficiency wrote

Let's see. Things like this;

http://www.ebay.co.uk/itm/1N60P-Germanium-Detector-Diode-FM-AM-TV-Radio-Detection-60-Pcs-/291059595034?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item43c480f71a

or these;

http://www.ebay.co.uk/itm/261375554771?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

That's what I was talking about. In spite of 1n60P being advertised as germanium it is in fact silicon Schottky diode, a replacement for 1N60 germanium. They do sound quite nice and they have low forward voltage. But not germanium I'm afraid. Unless you buy 1N60 from reputable source, most of them nowadays are from my experience schottkys.

As for transistors. That's just bunch of some of the most widely used types there are. There cost peanuts and at 3p a piece it's not bad, but that's whet they are really going for, unless someone is seriously ripping you off

[inefficiency]

Cool, thanks for the info.

Guess I'll be going for these bad boys instead!

http://www.ebay.co.uk/itm/50pcs-SFD112-NOS-Video-Detection-Germanium-Diode-universal-20mA-40V-VERY-RARE-/111366364452?pt=LH_DefaultDomain_0&hash=item19edf3dd24

[IvIark]

Those 1N60's look ok to me, just avoid the ones that look like 1N4148's because they're always schottky.  I haven't tried the SFD112s in anything yet but at that price I'd still recommend trying them.  In fact I may get some more

[tjdracz]

I thought that 1n60p were always schottky! Unless they are not p version

[IvIark]

They could both be 1N60 or 1N60P.  I've got schottky datasheets showing both numbers, and germanium datasheets showing both numbers.  But when they're DO35 they're always schottky although more often than not described as germanium (particularly on eBay)