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.
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?
Hello Mooly,
Thanks for the schema
can I use this circuit as a preamp ?
how should i make a change ?
Best regards.
Hello MarsBravo,
I found 2sd77 equivalent transistors. 🙂
Ac127, Ac176,Ac187,2sd30
Thank you for your interest
Best regards.
Attachments
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.
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.
There's enough germanium in the box.
I paid 2 pcs AC176 5usd 🙁
a bit expensive. because it is discontinued.
