Mooly's circuit referred above can suit this. It's an easy to modify universal circuit, often used for video amplifiers. I'll run a silicon mod if Mooly approves.
But, as Mark Tillotson points justly, things will be different making a direct comparision rather wacky.
But, as Mark Tillotson points justly, things will be different making a direct comparision rather wacky.
I've overlooked one small but very important issue: there is one npn (2SD77) in Mooly's circuit, but no npn on rediceman's list...
Sorry, but a no go for now unless rediceman can purchase 2 proper npn germanium bjt's.
Sorry, but a no go for now unless rediceman can purchase 2 proper npn germanium bjt's.
...unless rediceman can purchase 2 proper npn germanium bjt's.
Small Bear Electronics.
Spotted an error in the sim... I've forgotten the 470 ohm across Q6 B-E which will require a major tweak of R13 to around 10k
Anyone interested can have a play anyway 🙂
Anyone interested can have a play anyway 🙂
Yes do please, so the Siklai is more controlled.
The spike on ~1.5 kHz is a bit surprising.
The rest is devine up to 200-300 kHz.
You may be proud of it (considering a hardware copy @home).
Do you approve #41 if rediceman finds ge-npn's?
The spike on ~1.5 kHz is a bit surprising.
The rest is devine up to 200-300 kHz.
You may be proud of it (considering a hardware copy @home).
Do you approve #41 if rediceman finds ge-npn's?
I put together a small germanium headphone amp together some years ago, and its great 🙂
GERMANIUM Single ended Class A Headphone Amp.
Hello Mooly,
Thanks for the schema
can I use this circuit as a preamp ?
how should i make a change ?
Best regards.
I've overlooked one small but very important issue: there is one npn (2SD77) in Mooly's circuit, but no npn on rediceman's list...
Sorry, but a no go for now unless rediceman can purchase 2 proper npn germanium bjt's.
Hello MarsBravo,
I found 2sd77 equivalent transistors. 🙂
Ac127, Ac176,Ac187,2sd30
Thank you for your interest
Best regards.
Attachments
Hello Mooly,
Thanks for the schema
can I use this circuit as a preamp ?
how should i make a change ?
Best regards.
Yes it can be used as a preamp although you may want to look at using a higher supply voltage and also at the same time reducing the current in the output stage to keep the dissipation down.
Yes do please, so the Siklai is more controlled.
The spike on ~1.5 kHz is a bit surprising.
The rest is devine up to 200-300 kHz.
You may be proud of it (considering a hardware copy @home).
Do you approve #41 if rediceman finds ge-npn's?
Absolutely I approve as long as it's realised that you will have to alter the circuit to suit your exact needs. Remember this was designed to drive a low impedance load.
Here is a higher resolution sim and also a sim running into 600 ohms rather than 33 ohms and with a higher supply voltage. This one is delivering 1v rms into 600 ohm with a -15 volt rail.
Attachments
Ok, I'll suit it to -12Vdc supply and adjustable bias (5-50mA).
I omit the inputbuffer and volume (the input res may be replaced by a pot if preferred)
Just straigtforward as is with the given GE bjt's.
Considering a SI-variation for a two-channel left-right switchable box.
I omit the inputbuffer and volume (the input res may be replaced by a pot if preferred)
Just straigtforward as is with the given GE bjt's.
Considering a SI-variation for a two-channel left-right switchable box.
How many of each?
There's enough germanium in the box.
I paid 2 pcs AC176 5usd 🙁
a bit expensive. because it is discontinued.
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