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You'll have to analyze the circuit to figure out which is c, b, e and whether it is pnp or npn.
this guy sells germanium transistors: Vox Organ Germanium Transistors – Vintage Vibe
don't know if those are pnp or npn.
I've managed to replace germanium signal transistors with silicon in my schober recital organ.
You'll have to analyze the circuit to figure out which is c, b, e and whether it is pnp or npn.
this guy sells germanium transistors: Vox Organ Germanium Transistors – Vintage Vibe
don't know if those are pnp or npn.
I've managed to replace germanium signal transistors with silicon in my schober recital organ.
I'll try out to find about those, any advices on how to do that? Thanks for the link, it's sad germanium isn't more common, just like fets.
An externally hosted image should be here but it was not working when we last tested it.
Regards and thanks.
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Does this JVC preamp have a model number? Complete information may lead to a Service Manual or other data.
However if a Ge transistor is still working well, it is likely to out-live you.
Hello, it is a mcp-105 from december 1969.
Oh, I am actually counting on it. My greatest wish is that my children and hrand children can enjoy both craftmanship and quality of sound.
When I connect it, the starting mcp-105 set a lil noise, hearable only with ears on speakers, on the medium horn. The other medium speaker seems not to emit the noise but I should try out. It spitted big parasites one time but after moving all knobs a hundred times each and use deoxit. This never did again. However, if rca from computer is connected to it, noise become hearable, and if gpu is working out. It is hell, so I guess it takes all the bad noise from computer.
Regards and thanks.
Oh, I am actually counting on it. My greatest wish is that my children and hrand children can enjoy both craftmanship and quality of sound.
When I connect it, the starting mcp-105 set a lil noise, hearable only with ears on speakers, on the medium horn. The other medium speaker seems not to emit the noise but I should try out. It spitted big parasites one time but after moving all knobs a hundred times each and use deoxit. This never did again. However, if rca from computer is connected to it, noise become hearable, and if gpu is working out. It is hell, so I guess it takes all the bad noise from computer.
Regards and thanks.
In that case do NOT mess with it.
Besides cleaning pots , switches and connectors that is.
In any case you will NOT find that transistor at all, and those "musical instrument" germanium transistors still available are anything but what that preamp needs.
Plus after years of pruning, all that remains is "bottom of the barrel" stuff.
Okay, I won't then, I just cleaned the pots right now. The noise, however, that it does when I connect the preamp is a bit annoying cause I know it's there. Beside of that, the sound is just great, it's clear and undistorted. It's a very old piece that wasn't cared at all, the steel of the levers are rusted, so are some screws and yet...
I work a lot with vintage bicycles, so dirt is no strange to me, but how did some kind of that dirt that looked like earth, and some others black one and some cotton that wasn't removed from a previous service found itself here, I have no idea.
I can't fix properly the rca connectors at the bottom however, I removed most of the rust and they're shining again, but that's all I could do, there's still some rust.
I see, that's sad then, I'll fix some of the bad solderings then. A recap would it be in order or not?
Regards and thanks.
I work a lot with vintage bicycles, so dirt is no strange to me, but how did some kind of that dirt that looked like earth, and some others black one and some cotton that wasn't removed from a previous service found itself here, I have no idea.
I can't fix properly the rca connectors at the bottom however, I removed most of the rust and they're shining again, but that's all I could do, there's still some rust.
I see, that's sad then, I'll fix some of the bad solderings then. A recap would it be in order or not?
Regards and thanks.
Only the electrolytics, and only if some are off value for ESR. The Atlas Peak ESR meter has a chart of standard ESR values for different values capacitor & voltage.
Paper caps, depends on the brand. There were high quality paper caps in the 50's 60's that were dipped in wax and stay on value if the wax is not penetrated. Black GI's are famous from dynaco & scott equipment. There were sleazoid paper caps in some cheap brands TV radios that were just foil & paper wrapped up and tied up in celophane. Those went off value a long time ago, maybe just after the warrenty was expired?
A c meter may help you decide. I bought mine for $37 + freight from parts-express.com
Germanium is not thermally stable, and was used back then for certain uses only because it was marginally faster than silicon. Once the planar epitaxial geometry was perfected and the speed of silicon parts far exceeded germanium alloy transistors, there was absolutely no reason to use germanium - good riddance!
I can assure you that if there were a technical advantage to Ge, it would be used today. It's great fun if you want a low gain device that changes characteristics with signal current constantly, and may catastrophically run away if the load line is wrong, but most people don't enjoy that level of uncertainty or unreliability.
The transistors are not Germanium. That would be odd in 1969 Hi-Fi small transistors. The Service Manual shows neat 0.6V base-emitter drops, which is expected for Silicon but much too high for small Germanium.
This is a 3-stage phono amp. That's plenty of devices, they do not have to be special gain. They do want low-hiss but modern devices are pretty sure to be low-hiss (and are so cheap that if you get a hisser, you try another 13 cent transistor). 2N5087 looks suitable.
This is a 3-stage phono amp. That's plenty of devices, they do not have to be special gain. They do want low-hiss but modern devices are pretty sure to be low-hiss (and are so cheap that if you get a hisser, you try another 13 cent transistor). 2N5087 looks suitable.
JVC MCP-105E - Manual - Solid State Stereo Pre-amplifier with S.E.A. system - HiFi Engine
Here is the link for the manual but I don't see the reference to the 0.6v.
The amps of the series 104/105 are using germaniums in, for the 104 serie which is under, they used 2sb22 and 2sd30 germaniums inside.
I am gonna try to read more the manual however, you make me suspicious. Got an jvc ax-9 today as well, I am all excited!
Here is the link for the manual but I don't see the reference to the 0.6v.
The amps of the series 104/105 are using germaniums in, for the 104 serie which is under, they used 2sb22 and 2sd30 germaniums inside.
I am gonna try to read more the manual however, you make me suspicious. Got an jvc ax-9 today as well, I am all excited!
Ah yes, I see now, thank you so much. I knew there were some germanium in some amps of those series, according to what I readed on the internet. And with the look and name Gp marked over it, I guessed it was that.
Thank you so much! That's a relief for me as we never know what the futur holds and those poor parts are often badly used in the past, taking on their reliability.
Thank you so much! That's a relief for me as we never know what the futur holds and those poor parts are often badly used in the past, taking on their reliability.
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