Mix & Match Pre and Power amps

[Pr3Va1L]

Is it that simple?

Is there a way I could use parts from different circuits and make an amp with them...


Basically, I was thinking of building something like a 5E3 but I'd like to substitute the preamp for something a bit more high gain, that only uses 12AX7 and with only 1 input.

I'm looking for smooth gain in a 2x6V6 class A powered amp...


So the real question is... Say I use the circuit from a Mesa Mark IIC+ up to the power tubes (after the PI), will the output level be good for the power section of something like the 5E3, or is that something impossible to do?


Thanks a lot!

[daz]

You can simply adjust the PI values to match the pre and power. I have a 6v6 cathode biased power section mated to a preamp thats a JCM sort of affair thats got a ton of gain. i have a el34 amp with the same pre and they both sound great, but that 6v6 mated to a high gain pre really sounds killer for bedroom noodling. I like the sound of great preamp distortion added to a PA thats just starting to breathe a tad, and this gets it at TV levels. A marshall doesn't get there till small stage volume. I think you'll like it. I find it to be a great combination. it has a certain balance and compression i can't get with my bigger amp, tho it too sounds great. But it really needs to be opened up before you get the goods, a LOT more so than the 6V6.

[tubeswell]

Yeah I think Daz is rght - you have to build a really low-powered amp for bedroom noodling (something like 1-3W) that uses a couple of 12AU7s in push pull (or 6K6s or 6Y6s), with a small 5W-10W OT, otherwise it won't sing enough at bedroom volumes. You also need to figure in a bit of interstage padding and frequency manipulation to get the that over-driven pre-amp gain right, otherwise you'll end up with flabby mush (or something that barks like a dog), (or clucks like a chicken).

[txstrat]

If you go for a PP 6V6 power amp I'd think about a cathode bias since it adds more compression (for my ears great dynamics at relatively low levels).

[daz]

If you go for a PP 6V6 power amp I'd think about a cathode bias since it adds more compression (for my ears great dynamics at relatively low levels).

Absolutly. Mine was fixed at one point and i cathode biased it and it really sings with sweet compression at very low levels.

[Pr3Va1L]

Well, Isn't the 5E3 Cathode Biased? At least I thought so?


Anyways I'm not going for a super-low power amp... I want something that can be heard over drums, anyways... But I don't need the 50w I have right now.. So the 6V6s, I think, are a good compromise.

Since the original MKIIC used 4x6L6s, I thought 6V6 might be good enough to get the sound, at lower power so I could get some grit on the clean channel without going deaf!

So yeah, I've got an idea of the volume levels this will get.


When you say I need to adjust the PI values, you mean the capacitors after the PI?


Thanks for your replies!



EDIT: I've found out there's an interesting circuit for me out there..

Anyone got experience with the D-Lite 22? 2x6V6 with a Dumble Inspired circuit...

[drfunkphd]

So adjusting the PI values can match up say an SLO preamp with a 6V6 SE or 2 6V6 in PP, etc...?

[defaced]

From your other thread since they're about the same topic and other people are already posting in this one.

I need to adjust the amount of signal coming from the front end?

That's where I'd start. If you think of the two parts of the amp separately, (which they really kinda are from a purely functional standpoint), you see that if you have a working power amp, and feed it a signal of appropriate frequency/magnitude, it'll work just fine. It doesn't care what's going into it. Meaning, any preamp can work with any power amp with adjustment to its output signal. How they sound on the other hand is a different matter and one I can't really speak to because I've never tried every preamp with every power amp.

I would not mess with the preamp voltages too much unless you want to intentionally change they way the preamp sounds. Depending on how the two sections of amp are designed, you may need separate power supplies or other not-so-typical configurations. (see amp in link below)

So adjusting the PI values can match up say an SLO preamp with a 6V6 SE or 2 6V6 in PP, etc...?

People have already done it. Low powered SLOs aren't incredibly common, but they're out there. Start reading here: 5 watt SLO : DIY Fever – Building my own guitars, amps and pedals