Germanium circuit: 500 or 19" rack? For dirt/drive or colouration.

[stylesforfree]

Just posting this here to see what might be out there, sorry if it's in the wrong forum!

So, I already have gemanium fuzz and drive pedals for running my guitar into - one of my favourites is the Hudson Broadcast. I just love the way it sounds but it doesnt have enough headroom for line level instruments and I wanted to avoid buying a conversion box to match impedance, also it's not stereo.

Looking at my 500 racks I have a fair amount of modules to add some weight and colour to my drum machines, synths and tracks that I run out of my daw, but I was thinking about swapping some of the opamps on my API comps and CAPI BT50's which are currently loaded with 2520's. Im looking around to see if there's an API standard opamp that uses germanium transistors for some grit and drive.

I'm aware of the CA 0252 and the louder than liftoff rogue six, infact I think I have a VC528 with a pair of the 0252's in it.

I was also wondering if there is there any kind of DIY germanium unit, either 500 series (preferably of which I could use two) or a stereo 19" rack that utilises germanium opamps for dirt/drive/colouration? I think I would prefer to stick to as lower cost as possible and also something in the 500 series. Chandler is out of my price range and as far as I know TK audio discontinued the DP series preamps

Are there any kits or prebuilt opamps floating around that might add some significant colouration and drive? Or an off the shelf unit that can be modded relatively easily?

I was thinking about ripping apart 2 hudson broadcasts and building them into a small case and adding balanced inputs and outputs but my circuitry and electrical skills aren't really up to par.

Sorry about the direction of this post and the incoherence of my thoughts, it's kinda hard for me to break down whats in my head when I think of an idea or concept.

 

[Tekay]

Nice to see our DP preamp mentioned here! A new DP3 is beta tested right now and will be released soon.
About the Chandler germanium, their potted germanium amp block is more or less a Neve B104 amp = germanium version of the BA283 output stage. A funny thing is that the feedback and gain controls are doing the same thing, adjusting the negative feedback.

 

[gnarmageddon]

It's by no means the fun of building, but do check out the Kludge Germanium preamp for 500 series. Though I wish there were an output trim to drive the input a little harder, it is a heavenly sounding beast for when you want 'that germanium thing'. Priced very fairly to boot.

 

[stylesforfree]

Nice to see our DP preamp mentioned here! A new DP3 is beta tested right now and will be released soon.
About the Chandler germanium, their potted germanium amp block is more or less a Neve B104 amp = germanium versio of the BA283 output stage. A funny thing is that the feedback and gai controls are doing the same thing, adjusting the negative feedback.

Yeah, it's a lovely preamp and sounds incredible no matter what I throw at it! Awesome news on the DP3

 

[Mike Havok]

Here are a couple of germanium DOAs

https://groupdiy.com/threads/app-st...2-app14ge-germanium-doa-and-other-kits.33576/

https://www.zombierecaudio.com/5058g-kit

 

[Wavelength]

I love the Hudson as well, it's a super piece. Remember it's transformer coupled so you could easily put the back end into balanced. There some schematics around the net for clons of that to give you a head start.

 

[paulcheeba]

Zombie op amps are great germanium ones. Which I’ve put in all my modern API gear.

 

[Somkereki]

Yes, germanium transistors have a special sound! (Just think of Creedence Clearwater Revival recordings) I think they have a distinct germanium sound. (I wasn't there, I'm just guessing based on the sound) I used to have an 8 track / 1 inch studio tape recorder, I traded it for something else because it was so heavy, I already regret it.

 

[Wavelength]

Yes, germanium transistors have a special sound! (Just think of Creedence Clearwater Revival recordings) I think they have a distinct germanium sound. (I wasn't there, I'm just guessing based on the sound) I used to have an 8 track / 1 inch studio tape recorder, I traded it for something else because it was so heavy, I already regret it.

They have a more rounded clipping than silicon and also less voltage so ~0.3V compared to ~0.7V. So germanium is more like tube clipping in most cases.

 

[Somkereki]

I completely agree with you! For many years (the 60s) I started electronics with Germanium transistors. Towards the end of the decade, Silicon transistors came. Back home, we kids often bought transistors from Hong Kong "10 transistor" radios (where 6 actually worked) with the legs soldered to one point . They even worked at 100 MHz. Unfortunately, I'm already 70 years old, but this has become my hobby, and my excellent set of instruments (Tektronix, HP, R&S etc.) has remained. I repair, build, hi-fi - high end devices for many of my friends. For decades, I was a sound technical service engineer for Hungarian theaters. I even dealt with RF devices (microports). I also built power amplifiers for movie sound engineers operating from 12 volts, 600-800 MHz / max 15 Watt for field recordings. If they were filming in a forest or field, they needed a range of up to several kilometers, the 50mW officially allowed in Europe worked up to 100 meters. (Everyone had to hear the director's instructions.) There are also many Sennheiser MKH416 microphones on the shelf. And hundreds of Philips vacuum tubes in original packaging. I should make some excellent phono preamplifiers and ~ 15W power amplifiers, because only God decides how long I live I also studied vacuum tube manufacturing at university. Happy New Year 2025 and especially I wish you good health! (Unfortunately, I struggle with chronic Lyme disease, which they cannot cure, even though I have been in hellish pain for many years.) I don't wish this disease on anyone, not even my enemies. Now I'm looking for Rife healing frequencies. A colleague who is also an electrical engineer said that it might be my only hope. I've already been through 5 antibiotic courses, but they only brought 1-2 months of relief, even though the last 3 lasted 60 days each. With the antibiotic for Leprosy, and TBC. But my wife and I raised two excellent electrical engineering sons. My wife also died of pancreatic cancer 2 years ago. That's why I try to keep myself busy with my profession. At least many of my friends are happy about it.

 

[MidnightArrakis]

I completely agree with you! For many years (the 60s) I started electronics with Germanium transistors. Towards the end of the decade, Silicon transistors came. Back home, we kids often bought transistors from Hong Kong "10 transistor" radios (where 6 actually worked) with the legs soldered to one point . They even worked at 100 MHz. Unfortunately, I'm already 70 years old, but this has become my hobby, and my excellent set of instruments (Tektronix, HP, R&S etc.) has remained. I repair, build, hi-fi - high end devices for many of my friends. For decades, I was a sound technical service engineer for Hungarian theaters. I even dealt with RF devices (microports). I also built power amplifiers for movie sound engineers operating from 12 volts, 600-800 MHz / max 15 Watt for field recordings. If they were filming in a forest or field, they needed a range of up to several kilometers, the 50mW officially allowed in Europe worked up to 100 meters. (Everyone had to hear the director's instructions.) There are also many Sennheiser MKH416 microphones on the shelf. And hundreds of Philips vacuum tubes in original packaging. I should make some excellent phono preamplifiers and ~ 15W power amplifiers, because only God decides how long I live I also studied vacuum tube manufacturing at university. Happy New Year 2025 and especially I wish you good health! (Unfortunately, I struggle with chronic Lyme disease, which they cannot cure, even though I have been in hellish pain for many years.) I don't wish this disease on anyone, not even my enemies. Now I'm looking for Rife healing frequencies. A colleague who is also an electrical engineer said that it might be my only hope. I've already been through 5 antibiotic courses, but they only brought 1-2 months of relief, even though the last 3 lasted 60 days each. With the antibiotic for Leprosy, and TBC. But my wife and I raised two excellent electrical engineering sons. My wife also died of pancreatic cancer 2 years ago. That's why I try to keep myself busy with my profession. At least many of my friends are happy about it.

[I'm already 70 years old] -- I'm 75-years old.....almost 76 now!!! And, I'm "still kicking & ticking" designing equipment and PCB's for various companies and U.S. defense contractors. Right now, I have the very fortunate job of working with a defense contractor on a "100% FULLY-REMOTE" basis from right here-at-home!!! MAN!!!.....this means I don't have to go out and get into a freezing-cold car in the morning and hit the highway/motorway while dealing with crazy drivers at 80MPH!!! I am now able to design equipment here-at-home while dressed only in my underwear and eating a donut!!! HOW COOL IS THAT???

If either you and/or any of your colleagues/fellows over there in Budapest need any custom equipment designs created from drawings/sketches/written-information or PCB's from hand-drawn schematics or CAD-programs, let me know, OK??? It doesn't matter whether the needed equipment is either legitimate or "bootleg" (i.e., "RF" power-amplifiers). I just enjoy designing stuff, whatever it may be!!! (NOTE: And.....I have also designed more than my share of "down-low" equipment for various purposes)!!!

Here is a "GroupDIY" link to one of my responses in another thread from last year that will visually show you a large sampling of some of my equipment and PCB designs. Should either you or any of your colleagues need something designed, you can PM me and send me your information that way. We can exchange e-mail addresses later on from there. Here's my response link:

https://groupdiy.com/threads/thinki...anel-manufacturing-service.86050/post-1133167

>> I would also like to add that I am very sorry to hear not only your own struggles with health issues, but also of the passing of your wife. I am certain that that had to take a tremendous emotional toll upon you!!! I certainly do hope that you are now able to continue on with living a fulfilling life that brings you happiness and joy while doing the types of things that you love doing!!!

>> I WISH YOU WELL!!! <<

TAKE CARE!!!

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