at first stage preamp...pentode or triode?

i 'd like to get different opinions about preamps with pentode or triode in the first stage preamp.which sound with more musical harmonics.thanks.
cristian from argentina.

> ...preamps with pentode or triode in the first stage preamp. Which sound with more musical harmonics.

The distortion of triodes and pentodes, at the signal levels found in microphone preamps, is not very different.

Distortion is affected much more by choice of voltage, current, and load.

Microphone signals are weak. Pentodes have more noise (hiss) than triodes (for similar operating conditions). Pentodes are not usually your first-choice for weak signal amplification. Yes, there are a few excellent pentode-input mike preamps, but they require careful consideration of noise problems.

In general, I think a mike preamp should just amplify, without adding "musical harmonics". You have one chance to catch a great musical performance: you want to capture it and record it exactly. Then you can play that recording through various "color" devices (distortion, reverb, filters) and carefully compare different sounds. If you add "color" in the initial recording, and later decide it wasn't the right coloration for that performance, you are stuck. (Many experienced engineers do decide to add color in the initial recording, but this requires great experience and judgement.)

I agree with you.but there is something I dont understand.i have got a audio technica 4060 (tube mic), clon of 1272 neve and la2 with conventional components (including chinese cap´s).and sound much better than mackie preamps!!!.i wonder why??? 1272 add color or harmonics or what????.is it for design circuit? or for output transformer generates that?thanks!.
pd:i finished your design about 12au7 compressor and doesn´t work properly.can you help me?

and sound much better than mackie preamps!!!.i wonder why???

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that's like saying I have a Austin Martin vanquish why is it much better then a Ford Tarus.
I am sure the 1272 clone alone sounds better why it's probably not as noisey, has more gain on it and if I remember correctly has an output trafo. Now in itself the 1272 will color the sound a lil.but why ask why just enjoy...

pucho you right. but does 1272 give good cuality sound or or nice sound? and why???

Pentodes are great for mic pres if you use the good ones. (EF86, EF804S) You need to keep the plate voltage low, (V76 runs at about 67 volts at the plate, V72 a bit higher) and you also need to keep the screen voltage low, (about 1/2 of the plate voltage on the V72) .and the screen current low
(microamps on the V76)

Telefunken V72S (Beatles,EMI) and V76 are both pentode input.
Noise down 120 db.

Interesting story on the reason for the pentode, back in the old days Germany used to tax products by how many tubes thet had in them. The pentode had as much gain as two triodes, therby cutting the tube count down and reducing the tax.

At least according to Oliver.

cj what you say is very interesting.i was about to postpone my ef86 preamp project (an a old rupert neve design).what schematic do you suggest me to build before starting my project? .
emi consoles weren´t with transistor coupled by transformer?(dark side of the moon pre) or there exist a previous model with ef86?.
i would have to make a G9 and another with ef86 and draw my own conclusion (i have never heared ones w/ ef86 but i think it ´ll have a very interesting color of sound).thanks cj :wink: !!

I think pentode is the best option, with this yo get the best voives you will ever heard, also os you mix this with a ela m 251.

pucho you right. but does 1272 give good cuality sound or or nice sound? and why???

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If I remember correctly the 1272 although a line amp is spot on the the mic pre in a 1073. Can't argue with the number of tracks done over the years with a 1073 or a 1272 for that matter. IF you ask me if gives a good quality sound but that is my opinion.