Pignose 7-100 from 70's with Germanium transistors

59burst 1 on April 29, 2019

unfortunately, I’ve sold mine to buy some vintage capacitors months ago. I put it back on Reverb.com and a german guy took it off. I’m not sure if he’d reply back but I’ll ask him to take some pictures of the leads

dragonash 1 on April 29, 2019

a friend loves to play 2 of pignose amps through an ab box. i don’t know how they are old but i can tell they sound really good. i was about to get me an ab box then just realized i could do that with a delay pedal.

CongaFish 0 on April 29, 2019

@dragonash: kinda fun to “dasiy chain” two together, using one as a preamp, out into a 2nd one. But yes, they’re certainly much better-sounding with a simple delay pedal. Haven’t tried the A-B route… yet.

@59burst: Thanks. Think I figured the sequence out. (Emitter-Base-Collector / left to right? May try C-B-E?) Very low volume and hiss/hum/crackle before… but now mostly just low volume. Previously, 1 transistor & the 1Ω resistor were getting smokin’ hot. Now, no more high temps… but still no volume increase. The saga continues.

*Replaced the 2 (A&B in pic) germanium transistors & the resistor “C”.

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59burst 1 on April 30, 2019

sounds like a challenge to me. I still barely understand the electric circuit. I’ve read about vintage germanium transistors which can be used for NPN and PNP both, probably on a fuzz forum.

the only experience with germanium transistors was this project, btw

https://slowbean.net/search-threads/oc139

CongaFish 0 on April 30, 2019

I still barely understand the electric circuit.From 59burst

Same here, but I’m learning. Thanks for the link. I’ve a few other early solid-state amps that I’m working on, so I can take “breaks” from the Pignose when frustrated / stymied.

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dragonash 0 on May 1, 2019

didn’t see that huge one on the right side till now. actually most of them except for the karate kid’s pignose.

59burst 0 on May 19, 2019

@congafish the reverb.com buyer has replied. unfortunately, he didn’t like the sound of germanium and sold his pignose already

dlazzarini 0 on July 12, 2020

@congafish, i just acquired one of these old pignose’s. Not sure of the year yet but the pcb looks just like yours so I’m assuming 70’s. I was given the amp by a friend and its in need of some repairs it hasn’t worked in years. One problem that stands out right out the gate is a burned up capacitor. Im hoping one of you guys with some knowledge of these amps can help me identify it. Im not familiar with some of the labeling I’m seeing on the schematic posted above. It’s the brown colored larger ceramic looking cap located right next to one of the 2SB324H’s. I think its labeled “1E” on the above schematic. I could be wrong. I’ve never seen this type of labeling on a schematic. I’m hoping you guys could help provide some insight on this and help me identify this cap. any help would be greatly appreciated..

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CongaFish 0 on July 13, 2020

Hey @dlazzarini,

You talkin’ about the brown resistor labeled “C” in my photo above? That’s a 1Ω (Ohm) resistor. What does yours look like (pic?) is it “blown” apart / fractured, etcetera? Of course I was told that this is normally the go-to culprit to be replaced… as the leading cause of failure in these early Pignoses… but I have not been so lucky with the two ’73-’74 germanium-based Pignose amps here. Hopefully your luck will be better after only replacing that resistor and it’ll spring back to life. Hope so.

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dlazzarini 0 on July 13, 2020

Hey @CongaFish thanks for replying. So that’s a resistor huh? Sure had me fooled. I thought it was one of those old film caps. It looks just like the one in your pic with the “C” on it. Would you happen to know the wattage on that resistor? Something made it pop. What I suspect happened is somebody hooked up two 9v batteries to the 9v snaps that connect to the AA battery boxes. They were corroded out and I suspect they hooked up 9 volt batteries and gave it a dose of 18v.

CongaFish 0 on July 14, 2020

Dunno… but with the “touted” 5 Watts output rating ( an over-estimate for certain I’ve heard )… maybe order a 1Ω resistor with a 5 Watt rating (or 1, 2 or 3 Watts). They’re inexpensive and you could test a few different ones. As far as the 18 Volt damage theory goes… rumors have it that Frank Zappa ran his original Pignose with 18 Volts… and I have done the same on others here with no resultant damage.

Here’s a pic of a 25% larger “Big Pig” that I made, housed in a pine cab with a Jensen MOD 6/15 speaker. It’s basically a Pignose 7-100 upsized into a bigger cab with a bigger speaker and it sounds real “party” @9 Volts – until zapped with 12 or 18 Volts. After hearing a Dwarf amp and comparing it to a Pignose, I thought that maybe if the Pignose had a better cabinet & speaker it could better compete with the Dwarf quality. Nope. *I intend to build one at the exact same internal size as a Pignose with an original speaker to see how that might just compare… but I don’t hold much hope for that either.

The Dwarf amp also pictured (oak / wood stained near-black) with a faceplate of my own making. If everyone knew about the Dwarf amps (made only for two years in direct competition with the Pignose in 1974) there would be a lot more of them in the world. They put the Pignose to shame. (7 Watts!) AND porting the Dwarf out to closed-back extension cab with a 10” or 12” speaker… yields great tones and volume. Alas, the poor Pignose can’t do this anywhere nearly as well (and I have added “speaker out” jacks to several Pignose amps here).

AND if you really want to deep-dive into the early portables, there’s also the (now also very rare) Pygmy amp to consider. Offered as a build-kit from the PAiA company (also initially offered back around 1974) they were $39.95! AND still better than the lowly Pignose 7-100 IMHO.

Best thing about any Pignose?

The “Legendary” marketing.

(Best of luck with your Pig.)

Dunno… but with the “touted” 5 Watts output rating ( an over-estimate for certain I’ve heard )... maybe order a 1Ω resistor with a 5 Watt rating (or 1, 2 or 3 Watts). They’re inexpensive and you could test a few different ones. As far as the 18 Volt damage theory goes… rumors have it that Frank Zappa ran his original Pignose  with 18 Volts… and I have done the same on others here with no resultant damage.<a class="fe-zoom" href="https://s3-ap-northeast-2.amazonaws.com/slowbean/wp-content/uploads/2020/07/14023148/BPD1.png" target="_blank" rel="noopener"><img src="https://s3-ap-northeast-2.amazonaws.com/slowbean/wp-content/uploads/2020/07/14023148/BPD1.png" /></a>Here’s a pic of a 25% larger “Big Pig” that I made, housed in a pine cab with a Jensen MOD 6/15 speaker. It’s basically a Pignose 7-100 upsized into a bigger cab with a bigger speaker and it sounds real “party” @9 Volts - until zapped with 12 or 18 Volts. After hearing a Dwarf amp and comparing it to a Pignose, I thought that maybe if the Pignose had a better cabinet & speaker it could better compete with the Dwarf quality. Nope. *I intend to build one at the exact same internal size as a Pignose with an original speaker to see how that might just compare... but I don’t hold much hope for that either.The Dwarf amp also pictured (oak / wood stained near-black) with a faceplate of my own making. If everyone knew about the Dwarf amps (made only for two years in direct competition with the Pignose in 1974) there would be a lot more of them in the world. They put the Pignose to shame. (7 Watts!) AND porting the Dwarf out to closed-back extension cab with a 10” or 12” speaker… yields great tones and volume. Alas, the poor Pignose can’t do this anywhere nearly as well (and I have added "speaker out" jacks to several Pignose amps here).<a class="fe-zoom" href="https://s3-ap-northeast-2.amazonaws.com/slowbean/wp-content/uploads/2020/07/14022313/Group-A.png" target="_blank" rel="noopener"><img src="https://s3-ap-northeast-2.amazonaws.com/slowbean/wp-content/uploads/2020/07/14022313/Group-A.png" /></a>AND if you really want to deep-dive into the early portables, there’s also the (now also very rare) Pygmy amp to consider. Offered as a build-kit from the PAiA company (also initially offered back around 1974) they were $39.95! AND still better than the lowly Pignose 7-100 IMHO.Best thing about any Pignose?The “Legendary” marketing.(Best of luck with your Pig.)

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CongaFish 0 on July 14, 2020

*”Party” was corrected above – probably due to language.

dlazzarini 0 on August 8, 2020

Hey CongaFish you wouldn’t happen to know how to date these 7-100’s would you? All of my google searches are coming up pretty inconclusive. It’s got a low 4 digit serial number 3384. I can’t seem to find anything conclusive.