Got some "old TV parts" from Russia, looking for suggestions.

peccary

peccary

Well-known member
I bought 20 of these MP38A transistors from a seller on eBay in late February and just received them today.

I originally got them for an Aft PCB I've had assembled since about that time. I plan on plugging one in there and getting that built up, but I was looking for other suggestions for some builds where these would come in handy.

I randomly tested a few of them with a DCA 75 and for the hFE I got: 77, 102, 107, 88, 87, 106. ICleak for those were, respectively, .079, .235, .178, .097, .135, .156

I believe that this tester takes leakage in to consideration when calculating gain.

I'm looking for suggestions for builds. Anything that is bass friendly, or that can easily be modded to be so, would be a plus!

germ.jpg
 
fig said:
Maybe BB -> perf something....really nice numbers there!
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I still have my Si FF breadboarded, maybe I'll try plugging some in to that to see how it goes since it's NPN. I'm not sure if I'll have one that's high enough gain for Q2 but it will be fun to experiment with to see how things change. Think I'll play with that this weekend a bit.
 
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jjjimi84 said:
A point to point dirty boost or a tonebender
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Oh man.that would be quite the challenge - I've only even breadboarded one thing and that was using a cheat sheet. If I can find something super simple I will have to make it a point to give that a go. As long as I don't compare my end result with yours I'm sure I'll be happy :ROFLMAO:
 
peccary said:
Oh man.that would be quite the challenge - I've only even breadboarded one thing and that was using a cheat sheet. If I can find something super simple I will have to make it a point to give that a go. As long as I don't compare my end result with yours I'm sure I'll be happy :ROFLMAO:
Click to expand...

I can take some really detailed pictures and send them to you and help you along. It isnt any harder than breadboarding just more time comsuming.
 
@jjjimi84 and @thewintersoldier

Thank for the advice and offers of help - I appreciate it.

I am not sure what's possible so if I'm shooting at the moon let me know. Ideally it would be something that I could use on bass, but I do plan on getting myself an inexpensive guitar to play with as well, so I can use it on that, too. I am very much in to breadboarding something and tweaking with it until it's close, but if you could point me in the right direction of where to look I would appreciate that.

I think that in terms of tone I would like something warm that will break up in kind of spitty and mean ways in the top end and where the bottom won't drop out. I am not all that familiar with fuzz pedals other than the WM that I built, which used in a song or two when playing live, but it was way too much for something that could be used as a regular tone-shaper.

I'm not even sure what he's using here, it might not even be fuzz and I'm sure he's got more than just one effect going on, but the tone of the main guitar riff in this song has been haunting my dreams lately. It's warm and has a little bit to it but it comes apart when pushed. I know that a bass will never sound like that, but I'm talking more about replicating what that sound is doing as opposed to trying to recreate the actual tone, if that makes sense.

If the Dan Drive will get me part way down the road that would be great (I have your schematic saved) but if there is a better direction I should be looking I'm all ears.

 
thewintersoldier said:
With those numbers almost anything is possible. You could do a fuzz face but that is so blaze'. You want raw or nasty? Maybe a little of both? Something in the tonebender camp. Mk1 is the devil but in a good way, unhinged and raw, spits with attitude. Mk11 is more smooth but the has that bite still. Mk1.5 is a fuzz face without the blown out bottom end. Mk111 is the smoothest and less like mk1 and 2, very different topology but it has a tone control and is more flexible. The buzzaround is a variant of the mk111. It's the mk111 on steroids, more of everything:gain, volume and attitude. The dizzy tone is a tweaked buzzaround and the nastiest of the bunch. If the buzzaround is the devil the dizzy tone is the antichrist, the MF ain't playin around. I'm partial to the MK1 and Dizzy tone. Whatever you build determines what transistors are left and what options you can build from there. If you have questions I would love to help you piss off your neighbors and get the cops called on you!
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WOrD!

Dizzy Tone!

Based on youtube clip comparisons I've made, for fuzz the Dizzy Tone is my favourite gottabilldit.
Yes, "bill'd it" not "build it", 'cause the bill for those little grey elemental temperamental tone-trinket tiddly-winx...

That's what's holding me back from building all these TB & FF variants, the ¢o$t and associated scarcity.
2N3904? — got tons... OC-44? Only in my dreams.
 
My favourite Ge fuzz is the Marshall Supa Fuzz - made by Sola Sound for Marshall it's a Tonebender with bigger caps, so it's a big fat fuzz with more grunt than a typical TB. It's so simple to build on Vero especially if you have MP38s. You use the lowest gain first (Q1) and the highest gain last (Q3). It's a little tedious but it pays to socket the transistors so that you can keep trying different options. Once you get the right combination you'll know.

Marshall Supafuzz.png
 
I've spent the last couple of days taking a look at the suggestions here and I really think that I am liking the Dizzy Tone. I have seen a couple of demos that got my attention, mainly this one here using the Jext Dizzy Tone which just sounds unreal to me:


From what I have seen the Jext was based on an original Elka, so I think that is what I am going to go for. I think I will breadboard it first and play with the different transistors. Looks like y'all are going to make me bust out the vero - something I wasn't sure I'd want to do again after discovering this palce!
 
Just tested each one for gain. Its' about 74 in my house right now and I did my best to not touch them with anything other than the test leads. I love the little grabby ones that come with the DCA 75 - pretty handy.

The 58 and 136 are the oddballs, it seems.

Is the general rule of thumb once I get this built on the BB to go low to high Q1-Q3, mixing and matching till the mojo gods smile down upon you?

gains.jpg
 
thewintersoldier said:
I can give you the values to use the gnat board, it's what I built mine on. I have post on Madbean forums all about it. The dizzy tone is my favorite and I took a deep dive looking up original schematics and info about transistor gains
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I saw this post from back when, Did you build end up building it on the Gnat?

Buzzaround to a DizzyTone

I haven’t tried this yet but looking at both layouts I think this is how you convert the Buzzaround board to a DizzyTone R2 150k R3 680k R8 15k R9 18k C2 25u C3 25u C101 25u Sustain C250k Balance B5k Attack A1m
forum.pedalpcb.com forum.pedalpcb.com
 
music6000 said:
Don't overlook this, Voltage converter so you can Daisy chain it !
www.pedalpcb.com

Gnat Fuzz - PedalPCB.com

Compare to Burns Buzzaround
www.pedalpcb.com www.pedalpcb.com
Click to expand...
If I could get a PCB which would allow me to use the same architecture while modifying the component values that would be my ideal.

I'm still learning most things right now, so I have to ask: what is the purpose of the voltage regulator there?
 
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