Yes , a germanium preamp the noise level is greater than that of silicon devices . Germanium but the sound is very musical ... Yes, and the noise level is still much lower than noise LP records .....The basis was applied to a circuit Telefunken . Was added a buffer stage and applied stabilized power supply ( assembled with germanium transistors )...............I made a few Phono preamp with transistors J-FET . They had a small noise and good sound . But still the sound of a germanium preamp more emotionally...
You would not believe i still have in my possession an old Sparta studio broadcast phono preamp. All germanium. With trafo on output. I recapped the thing, an it works fine, sounds great. Very musical. I do have many much better phono preamps, but this one is a keeper. Now more than half the century old, likely...
I have used the mp26a for prototypes and it has worked well. I purchased them a few years ago on ebay from:
gordelux04 on eBay
had no problems considering such a distance to Texas.
I also went back later and got some power germanium.
cheers
gordelux04 on eBay
had no problems considering such a distance to Texas.
I also went back later and got some power germanium.
cheers
Schematic germanium phono preamp and power supply ..... Germanium phono preamp ( sch.) - Vinyl Engine , Power supply for germanium phono - Vinyl Engine .
Interesting, this thread. Some people prefer silicon, some germanium transistors. As a kid I experimented with battery powered amplifier circuits using both germanium and silicon transistors. I still remember how the germaniums had that nice sound and the silicons sounded lifeless. I decided recently to resurrect a circuit in which I could change the transistor type and the gain and frequency response would be much the same. All that would change would be the harmonic distortion. It was a simple class A headphone amp using a silicon BD140 output transistor. The input gain transistor was the one I could change. The modern small silicon transistors such as 2sc2240 and bc549/bc849 sound very accurate and clear. The germaniums I tried all sound different to each other yet seem to have a family sound. Generally warmer, more depth, noisier and less perfect. As the weeks progressed I preferred the germaniums and the silicons were left in the drawer. I love that smooth, lively sound they seem to make their own. More entertaining to listen to.
Monacor/Monarch SA-616
... as example.-)
Four-stage-line-power-amp (se-se-se-trafo-pp). But use good speakers and sources,-! You must be very experienced with! Not a horrible big multiway, produced by idiots, used by unskilleds-! Not any big CD/SACD-reference-player, produced by idiots, used by unskilleds!
Tune a little bit (remove the first and the second stage, new-solder, remove some switches ... as example) and start to dream. Very fine, very open, very cultured! Nearly a very very very good se!
... you will remove your XXX-amps,-! No doubt,-!
... as example.-)
Four-stage-line-power-amp (se-se-se-trafo-pp). But use good speakers and sources,-! You must be very experienced with! Not a horrible big multiway, produced by idiots, used by unskilleds-! Not any big CD/SACD-reference-player, produced by idiots, used by unskilleds!
Tune a little bit (remove the first and the second stage, new-solder, remove some switches ... as example) and start to dream. Very fine, very open, very cultured! Nearly a very very very good se!
... you will remove your XXX-amps,-! No doubt,-!
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I suspect a key difference in sound is gm, Ge parts have lower gm than Si. Same with tubes, many prefer sound of low gm tubes.
The hfe of the various germaniums I used were between 50 and 100 at 1ma. I also tried silicon transistors mpsa06 and mpsa42 in the same position in my headphone amp and they sounded boring! The germaniums with similar hfe were full of life and character. I'll need to get out the distortion analyzer and see what's going on.
As far as low gm tubes is concerned, I've always preferred the high gm ones like 417 and good ecc88s. They have more drive, lower distortion and lower noise.
As far as low gm tubes is concerned, I've always preferred the high gm ones like 417 and good ecc88s. They have more drive, lower distortion and lower noise.
Wow I remember fiddling with circuits like this in the 90s except I used 6sn7s and BD140s. I remember that the tube needs about 30v across it to obtain reasonable linearity.
Just looked up the specs for an MP26A. It can handle about 70v, with a 200mW maximum power dissipation. I guess at those higher voltages the c-b leakage would be high and influential though.
Just looked up the specs for an MP26A. It can handle about 70v, with a 200mW maximum power dissipation. I guess at those higher voltages the c-b leakage would be high and influential though.
its quite impressive on the analyzer.
i uploaded the plots another thread using fet , if get time will do the mp26 plots here too.
magically the topology does not seem to care about leakage or device varations.
i have not used with a worn out 12au7 yet.
i uploaded the plots another thread using fet , if get time will do the mp26 plots here too.
magically the topology does not seem to care about leakage or device varations.
i have not used with a worn out 12au7 yet.
Hello,
You can still buy headphone class A amplifier with germanium transistors:
- AMPLIFICATEUR DE CASQUE STEREO - TSM "ampliatubes.fr"
You can still buy headphone class A amplifier with germanium transistors:
- AMPLIFICATEUR DE CASQUE STEREO - TSM "ampliatubes.fr"
Hi, Thank you for sharing this schematic. i made it with my ac128 and b405 and sounds very good .
I recently made a new phono preamp using germanium transistors . It contains transistors AC-122 ( Telefunken ) and GT308 , MP-37 (USSR ) . The preamp has a rumble filter .Powered by 24 volt batteries ...
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Brave 🙂
My guess is the AC122 is the input device as the rest have atrocious noise performance. Have you done any noise measurements?
My guess is the AC122 is the input device as the rest have atrocious noise performance. Have you done any noise measurements?
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Joined 2009
Paid Member
I love it !
A nice clean aesthetic, something a bit special in this day and age. Looks like a really nice project.
The first 3 transistors (this is a Phono-preamp ) are used АС-122 . The rumble filter is assembled on GT-308 & MP-37. Noise measurement gave a result of - 75 dB with an output signal of 2 volts from peak to peak ( RMAA) ....Now I'm installing the board in the aluminium case . When everything is done , I will show you the result and the scheme .