Analog Tube Power amp simulator: studying possibilities

Not sure I understand what you're after...

The Mofeta and the Thunderbird are pedals, preamps if anything. They don't have poweramps.

So you could run either one into a real tube-preamp and speaker emulator of some kind.
No they're not. They are preamp + poweramp emulations. Hence my question: can I drive the poweramp section of any of these circuits with a REAL tube preamp and use a speaker emulator after the poweramp emulator without impedance problems? If so, would a buffer be a good idea akd a fix?
 
Keyword = "emulations".
They don't have power-amp sections.

So you want a "REAL tube preamp" > Mofeta/Thunderbird > speaker emulator...
I don't see a problem with that. A buffer shouldn't be a problem, neither the Mofeta nor T-bird are like a Fuzz Face.

Have you looked at the Mofeta and T-bird schematics to determine which part is emulating the amplifiers?
I'm guessing for the PPCB Mofeta, the power-amp emulation comes after the tone-stack at C15, but then you lose a big part of what makes the Mofeta sound like it does.

For the T-bird, I couldn't say what's "power-amp", to my eyes it looks like the whole circuit is part and parcel.

What sort of speaker emulator were you thinking of using?


I'll hope someone more knowledgeable steps forward and hopefully answers conclusively, as I'm just but a lowly padawan.
 
Would it be possible to use the poweramp section of, say the Mofeta or the Thunderbird, with a REAL tube preamp and a speaker emulator after it?
Would there be an impedance mismatch between the preamp output and any of these poweramp's input?
If so, would that be fixed with a buffered output to enter the poweramp with a low impedance signal?
These parts aren't strictly power amplifiers. They only simulate certain aspects of PA "sound" and behavior.
 
For me there is a difference between listening to a simulation and playing/feeling one.
A friend of mine plays with a UA plexi pedal and an active Fender FRFR monitor. I like it when he plays it. I need that under the fingers feeling.
I like this video of the Wampler Pedalhead but I am afraid the latency 0,75 ms would still be a problem for me.
I have a Red box speaker simulator but because of the noise it produces it is collecting cm's of dust
 
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These parts aren't strictly power amplifiers. They only simulate certain aspects of PA "sound" and behavior.
Thanks for your reply. I'm aware they aren't strictly power amplifiers, hence my question :)

What I'm trying to achieve is to build a box into which I can plug a real tube preamp at the input and a mixer/soundcard/SS amp/FRFR monitor at the output abd make it sound an d feel like a tube amp :)

I've tested a setup consisting of a tube preamp into Deadastronaut Astrosim and it sounds quite good but the feeling I have is it lacks the dynamics a tube amp has. When I play soft it responds but when hitting the strings hard it goes "thin". My guess is I need a poweramp emulation to achieve or get closer to that "feeling" (maybe I'm wrong).

So I was wondering if the Thunderbird or the Mofeta (since they include a poweramp section emulation) would serve that purpose.

Any input is very welcome and appreciated.
Cheers
Sono
 
Why would a solid state pedal based on a solid state amp with some "power amp emulation" which just means they threw a weird gain stage running transistors at 18 volts make it feel like a tube amp? (Referring to the mofeta)
No it won't help. It might sound good.
 
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Why would a solid state pedal based on a solid state amp with some "power amp emulation" which just means they threw a weird gain stage running transistors at 18 volts make it feel like a tube amp? (Referring to the mofeta)
No it won't help. It might sound good.
I've already stated a couple of times thta it's based on a REAL TUBE PREAMP.
The preamp has two 12ax7s working at 330VDC...
🙄
 
make it sound an d feel like a tube amp :)
Good luck.. :)

When I play soft it responds but when hitting the strings hard it goes "thin".

This can be interpreted in different ways. No bottom end? No punch?
If it's a tonal issue, maybe try graphic EQ?
Or something like Presence and Resonance from Bajaman? https://www.freestompboxes.org/viewtopic.php?t=29369
Or maybe a Simplifier? https://forum.pedalpcb.com/threads/ly-rock-tone-monster-clone-dsm-humboldt-simplifier.20668/
Or..
 
Thanks a lot for your suggestions, Temol :)

Good luck.. :)

I know....but we gotta keep trying!! ;)


This can be interpreted in different ways. No bottom end? No punch?

Yes, more like no punch, like the note's attack gets shattered/compressed. Not easy to explain :)

https://www.freestompboxes.org/viewtopic.php?t=29369
I did try the Simplifier but TBH it sounds a bit sterile to me... at least I couldn't make it "sound"...
https://forum.pedalpcb.com/threads/ly-rock-tone-monster-clone-dsm-humboldt-simplifier.20668/
Or..
Has this been traced at all or is there a schematic for something similar? I'd rather build my own box


Am I mistaken or these are digital units? As a building hobbyist, I'd rather stay away from digital (at least for now hehe)


Or something like Presence and Resonance from Bajaman? https://www.freestompboxes.org/viewtopic.php?t=29369
I just read through that thread and that Bajaman circuit sounds (no pun intended) quite interesting and promising actually.
I also realized that I missed your post on the first page of THIS thread where you mention many Bajaman circuits that all seem to include a poweramp simulation...🤦‍♀️
Also, on the thread you linked about Bajaman's Presence and Resonance circuit, there's a link to Bajaman's Reactor. After also reading that thread I've got a couple of questions that maybe you could clarify for me :)

- The poweramp sims on the Bajaman circuits (Humble, TW, HiWatt, 5e3, etc) are they the same as the P&R circuit, or more like the Reactor, or a completely different approach?

- Are the Thunderbird or the Mofeta power stages any different or the same concept?

- You seem to have built and heard a few of these circuits. Which one would you recommend to build and test, using a tube preamp and Deadasronaut's Astrosim as a speaker emulation into a mixer?

Again, thanks a lot for all the information, the links, your time and help :)
Cheers
Sono
 
I've already stated a couple of times thta it's based on a REAL TUBE PREAMP.
The preamp has two 12ax7s working at 330VDC...
🙄
It seems I got mixed up and thought the mofeta was based on the beta lead for some reason. However the tube feel is generally regarded as coming from the power amp. So if the tube feel is coming from the power amp then your tube preamp won't give it especially if your tube preamp is not doing it for you already. And I don't think that whatever power amp emulation circuit in the pedal is actually gonna do the job. Maybe I'm wrong. Have fun
 
I'm actually going to suggest also looking at tube powered DIs. There is a company that does diy boards for a couple projects that post here. The site is called Conspiracy to Commit Electronics, give them a look to see if it's something that could work.
 
Yes, more like no punch, like the note's attack gets shattered/compressed. Not easy to explain :)
Uneducated guess would be:

Low power strum = less ac mV getting into circuit and circuit clips in a behaved way resulting amplifying signal toward the output

High power strum = more signal strength to input, grid/base/(gate?) blocking happening and there’s just too much clipping going on so signal chokes to wasp buzz

Solution could be attentuating AC signal between amplifying/clipping circuit stages?
 
However the tube feel is generally regarded as coming from the power amp. So if the tube feel is coming from the power amp then your tube preamp won't give it especially if your tube preamp is not doing it for you already. And I don't think that whatever power amp emulation circuit in the pedal is actually gonna do the job. Maybe I'm wrong. Have fun
Well, actually I think you're right and wrong :)
In Marshall style topologies the poweramp has an important part on color, texture, distortion etc. Fender topologies, due to their headroom are more transparent.

I also agree with you about tube emulation is not going to be like a tube amp but I'm just trying to get as close as possible. At least trying to get far from that "line-out" sensation as much as possible, if you know what I mean :)

I'm actually going to suggest also looking at tube powered DIs. There is a company that does diy boards for a couple projects that post here. The site is called Conspiracy to Commit Electronics, give them a look to see if it's something that could work.
Actually that's probably not a bad idea at all, especially for the DI Output part. Thanks for your suggestion :)

Uneducated guess would be:

Low power strum = less ac mV getting into circuit and circuit clips in a behaved way resulting amplifying signal toward the output

High power strum = more signal strength to input, grid/base/(gate?) blocking happening and there’s just too much clipping going on so signal chokes to wasp buzz

Solution could be attentuating AC signal between amplifying/clipping circuit stages?
That seems to make sense, but where? I mean, that's probably not happening in the tube preamp, so would that be in the speaker sim part?

Thanks to all for your help and ideas :)
 
That seems to make sense, but where? I mean, that's probably not happening in the tube preamp, so would that be in the speaker sim part?

Thanks to all for your help and ideas :)
Either trace the signal with oscilloscope to see waveform changing or audio probe to see where signal loses it strength?

Could you share preamp schematic?
 
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