The driver also appears to be relatively high in distortion. Actually there are some preamp out there using the , Audio Note preamps and the Arthur Loesch preamp come in mind. The input tube is configured as a grounded-cathode amplifier, but its cathode actually “grounds” into the SRPP’s output. I am not into pleasing sounding amps, I’d want all-out performance please. Ryan, As you can see from my sig. You missed the point

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I pointed out 567 the circuit was internally at odds with its overall function, as two of the four stages within their design fought each other; and that by simply transposing the two stages, the entire amplifier would work much better.

5687 SRPP Line Pre Amp (with Power Amp)

In other words, about 50 times better than a single ECCbased cathode follower would deliver and 25 times better than two ECC99 srp parallel could yield. Interesting, but also depressing. In the mean time it looks similiar to this output stage: Just need to get some caps, got everything else. I don’t know if the Seth is ‘fun or lively’ for any but a few.

Since the negative feedback loop encompasses the cathode follower, the cathode follower’s output is under the control of the input triode. When used as an amplifier, many falsely imagine that it offers a low output impedance, which it seldom does. Newer Posts Older Posts Home. Sr;p Dan, welcome to the forum!


Yes, both topologies are in parallel with each other. I only guess this, after measuring similar power transformers, which were over Ohms DCR.

Anyone who dares challenge the supreme truth is a misguided fool. Not as much GM as the variants, but super linear.

Being a three stage amp, really – ANY – three stage amp it will sound less transparent that an equally well built two stage amp. Then all you have is the amplified AC audio signal.

It’s all there, black and white, clear as crystal! Fri Sep erpp, 4: Register a new account. Might I suggest building a Morgan Jones? So, I could be wrong about which would work best; or, put differently, it depends on how good the power supply is.

Well, to be more precise, in the output stage.

DIY Audio Projects Forum • and 6NS7 Tube Preamp designs

Hi tubediyer Would you post the circuit diagram of the “6dj8 direct couple “? I didn’t see anything in the Tube FAQ’s on the amp page, and Google hasn’t been very supportive either, 55687 do you know of any other resources? Thank you for understanding.

For example, with V2 being a 6DJ8 or or ECC99, we would expect an output impedance of about ohms, so two triodes would deliver wrpp output impedance of about 50 ohms.


I’d like to avoid going DC unless it’s absolutely necessary. If there is difference, the input triode’s plate moves in the opposite direction, which causes the SRPP output stage to move its output in line with what the input triode’s grid sees.

If you want to mentally enthrone it, fall in love with it, well Georgie, please. Which xrpp would work better?

DIYParadise 5687 preamp

Hope more high hand can provide some information for me. He may have figured that parallel capacitors would result in a lower ESR value than using a single 50 uF capacitor. With the 6K load on the driver you get 1. Yes it’s in the signal path as it is the coupling cap. Actually V allowing for resistor drops. I love the sound of the KT88, I wanna turn it up a couple of notches.

TK, We also need to add three cathode followers too, to make it low in Z, and why not about three cap couples too!!