♫♪--My little posh Tringlophone--♪♫

[danielwritesbac]

My computer definitely has trouble pushing an 11w amp with 26db gain. What gain does Tringlophone have?

[Elvee]

Originally Posted by lineup

Any capacitance added increase distortion. You have not this trouble in this amplifier here.

Excessive capacitance can degrade the performances, but all feedback amplifiers require some compensation.
Properly applied capacitance makes these amplifiers possible.

Originally Posted by danielwritesbac

My computer definitely has trouble pushing an 11w amp with 26db gain. What gain does Tringlophone have?

The gain is set by the ratio of the 330R and 3K9, in this case 21.5dB.

If you find it too low you can decrease the 330R, but R25 should follow R23 to keep the bias correct. Some tweaking might be required to retain the maximum dynamic, as the system works open loop

[padamiecki]

Elvee
I have ~10 pcs of KD502 and KD503 transistors http://www.elenota.pl/datasheet-thum...t_125964_0.png
can I use them directly instead of 2N3055?

[Elvee]

Originally Posted by padamiecki

Elvee
I have ~10 pcs of KD502 and KD503 transistors http://www.elenota.pl/datasheet-thum...t_125964_0.png
can I use them directly instead of 2N3055?

They look perfect

[terranigma]

Originally Posted by Elvee

You are free to use darlingtons instead: the circuit will work almost identically, but with less headroom and a reduced linearity, but nothing really alarming.
And such a circuit will certainly be more placid.

Elvee, could you provide at least a sketch to show how manipulate NPN darlingtons on the original schematic?

It seems my to-do list will rise again by following your "little" designs. I like the way of your using big and small metal case transistors everywhere.. I like the oldskool fashion

[Elvee]

Here is the adapted version, tested in sim only (but it should be more placid than the CFP).

As expected, it has less swing and linearity, but nothing catastrophic.

[terranigma]

Originally Posted by Elvee

Here is the adapted version, tested in sim only (but it should be more placid than the CFP).

As expected, it has less swing and linearity, but nothing catastrophic.

Thank you very much Elvee. I felt a bit ashamed by seeing redrawn of whole schematic. Your kindness as usual.

If different type of transistors were used (original or darlington), can you elaborate that which parts of the circuit going to be considered for fine tuning? I'm sorry but I can't read the circuits like many people here.

At last, I bought an analogue 20mhz oscilloscope. Remarkable improvement for an electronics hobbyist. I expect that I could do some fine tuning on my builds but my theoretical base is at very early stage. I hope to improve my skills in time.

[Elvee]

Originally Posted by terranigma

If different type of transistors were used (original or darlington), can you elaborate that which parts of the circuit going to be considered for fine tuning?

First, you could look at the differences between this schematic and the regular one, beyond the simple sex-change: there are many, some quite subtle.
There is certainly still place for refinement on those departments.
Then you can test the effect of different values in the stabilization networks.

[terranigma]

I'm collecting parts of Tringlophone and some questions become to consider somehow.

For Q13, is Vce critical? Is higher Hfe preferable?

For 2N2905A's.. In case of mixing different brand/ranking transistors, can we group 2905A's ? If so, which ones is not critical in terms of Hfe? I mean can we use somewhere 2N2904 (Reduced Hfe version of 2905) without any side effect?

Same for 2N2219A's.. Can we group these ones, or is it beneficial to use same rank transistors everywhere?

[Elvee]

Q13 needs to have a Vceo greater than Vs-7V approx., in this case 25V is sufficient.
The Hfe is preferably high.
Q6 and Q8 should be identical. Other than that, you can use and mix 2N2904 or 2N2905 everywhere in the circuit.
There is no constraint at all on the 2N2219.