more preamp stages?

[iknowjohnny]

Just curious...what would you say are the ramifications of adding another stage to a high gain preamp and then accomplishing the same level of gain so that each stage has to be overdiven less? Less dynamic? More? What advantages and disadvantages do you see besides the unimportant ones like cost, noise or more wiring ? Just tonal observations.

[DonMoose]

You could try a PV 5150 vs something with fewer stages (sorry, don't know what would be comparable).

Hope this helps!

[iknowjohnny]

Well, curiosity killed the cat. In this case it just killed my hope. Hope that using the extra stage i have as another gain stage since i $hit-canned the CF would be good. So i added it with another gain pot. Tired one gain down and the other up, visa versa, both in the same position.....observation.....3 stages sound better than 4 ! Of course if you want hyper gain a 4th is good i suppose. But i prefer the sound of a clean boost to get hyper gain.

So, back to the switchable CF/plate fed tone stack. As i said recently i prefer the plate fed but i do find at times it's a nice change to go back to the CF.

[VacuumVoodoo]

There's a major difference between adding a gain stage before the 1st vs. after the last in a preamp. Imagine putting your clean booster after the preamp....

[iknowjohnny]

There's a major difference between adding a gain stage before the 1st vs. after the last in a preamp. Imagine putting your clean booster after the preamp....

Whats the difference when you have 3 stages or 4? The one i added just makes 4, what does it matter where i put it? lets say they're all configured the same for sake of argument...what does it matter where i put the extra stage ! See what i'm saying? if i put it in front, the first stage now becomes the second, the second is now 3....etc. It makes no difference. You have 4 cascaded stages in a row no matter how you do it !

[VacuumVoodoo]

Read my post again in context of you preferring a clean boost in front of the amp. Then analyze gain sequencing in a 3 stage preamp. Of course if all 3 stages are identical with identical attenuation (or none?) in between then it doesn't matter where you add identical 4th.

[iknowjohnny]

i'm still not quite sure what you meant, but i think you may have misunderstood what i meant about the clean boost. I meant that i prefer a clean boost pedal to drive the input harder to getting the same amount of gain by adding another tube stage. But i wasn't adding another gain stage for that reason anyways. I was doing it to see if 4 stages that are overdiving less would be better than 3 that are overdriven heavily. I found i prefer the latter and prefer a clean boost pedal to 4 stages if i want hyper dive.

[Jana]

+1 what Aleksander said. Read his posts yet again.

You tacked the gain stage on the end. You already have shaped and boosted the signal and run it through the tone stack and then added a gain stage. Putting that extra gain stage on the front end is going to be quite a bit different--it will be more like your clean boost setup.

And who says you have to have "hyper dive [sic]". That extra stage could be used for a slight boost but more so for tone shaping.

[iknowjohnny]

I didn't put it after the tone stack if thats what you're saying. I put it after the 3rd stage, so i just had 4 stages in a row.

[Jana]

Did you experiment with the various components? ie. plate load resistor, cathode resistor, bypass cap, coupling cap, etc. Remember how much tinkering you have done with the amp already? Well, you now have one more gain stage that you need to tweak--by itself and in its relationship to all the other gain stages. Not only that but you have the position in the string of gain stages to tinker with.

Maybe you are a 3 gain stage person. But how will you know for sure until you spend the next few years tweaking and experimenting with as many variables as possible?

[iknowjohnny]

I tried a few things, but it was obvious right off the bat that i wasn't going to find anything better with 4. I thought maybe the entire character of the gain might change in some way that might be worth investigating, but no. Just an experiment that i figured was worth trying since i have this extra ax7 side thats unused. Actually, like i said i did have it hooked up as a CF stage and made it switchable between plate fed TS and CF fed. But i use the CF so little i figured maybe it might be good to use if for something else. So for now it's switchable again and if i get a wild hair maybe i'll do something else with it like a return amp for a loop or who knows. Till then i'll leave it switchable.

Now, quit teasing me....i'm very sensitive ya know !

[guitarmike2107]

you got rid of the CF, which helps smooth out the high gain tone... its not really the same comparison, you lost part of the circuit to add another. try just adding a triode stage and keep the CF

[Ripthorn]

One thing I just tried last night that i quite like (in terms of using an unused ax7 side) is to do different input gain stages that can be switched to do one or the or both in parallel. I made an express preamp where I can switch the first gain stage between normal and a plexi or put them in parallel. Love the possibilities there. You could do something like that.

[iknowjohnny]

I thought about doing parallel actually. But i've tried that b4 and while i liked it somewhat It isn't something I think would be as useful as having the option of a cathode follower stage i can switch in. But i may give that a go when i have the energy and drive to try that. This is all in fun anyways because the amp already sounds great. I just like trying things now and then. Sorta like panning for gold when theres nothing better to do in hopes of getting lucky.