High gain practice amp to diy

[cytt0rak]

Hello great people of diystompboxes.com,

I've have learned main parts of pedal building now I want to expand in to amplifier business, I want to build a hybrid amp (tube preamp non starved plate, solid state power amp). Before that I'm looking for a amp that I can build without exposing myself to deadly voltages, have fun and change some parts to achieve different voicings. Thanks.

[Elijah-Baley]

Hi! Nice idea.
I don't know if you can find an high gain tube preamp, maybe a fet version preamp, mesa-soldano-diezel style. But then it is not an hybrid.
I know it is not your target, but maybe you can build an overdrive tube preamp and to use a pedal distortion.
What SS power amp you want to build?

[Marcos - Munky]

Just to be sure, the amp you're building now is solid state, right? How many watts are we talking about?

[cytt0rak]

Hi! Nice idea.
I don't know if you can find an high gain tube preamp, maybe a fet version preamp, mesa-soldano-diezel style. But then it is not an hybrid.
I know it is not your target, but maybe you can build an overdrive tube preamp and to use a pedal distortion.
What SS power amp you want to build?

I could just build a normal tube preamp and use pedals yeah, problem starts within power amp section cooling, enclosure, power supply makes everything complicated. I have seen some builds with transformers but I'm not really experienced with them I would probably end up blowing the house right now. I have some wall warts from leftover computer gear like 15v 1A dc adapter. Maybe I could build ss power amp and tube preamp seperately.Thanks for the answers.

Just to be sure, the amp you're building now is solid state, right? How many watts are we talking about?

Sorry for my English I'm not good as its not my native language. I want to build a solid state high gain amp that can handle a 2x12 for both practice and test benching trying different ideas. I'll use the power amp section from this build and integrate it to a plexi like tube preamp with preamp clipping. I have been reading on tube stuff for a long time. Thanks for the answers.

[Marcos - Munky]

I think you can power a TDA2003-based amp with those dc adapters. If your 2x12 have 4 ohms impedance, you'll get around 6W of output, which is loud enough for practice but not loud enough for rehearsal. I don't know if you can use it with a 8 ohms speaker.

Since you're planning on use this power amp later with a tube preamp, I suggest you to build a 60W-80W power amp using a LM3886 or a TDA7294. But you'll need to build a power supply for these amps.

Also, be aware that even a tube preamp have deadly voltages, if you decide to build one.

[sajy_ho]

I had the same idea last year and I used a plexi-ish preamp(from AX84 Hi-Octane) in front of LM3886. It sounded good but not as good as a real tube amp with output tube section. After that I changed the tube preamp with a nicely designed solid state preamp (ROG Thunderbird); man it came to life!
I,ve played it in front of a group of friends and none of them believed it's not tube!
IMHO tube preamp is not a critical part of the tube sound and can easily been simulated by SS circuits; so don't bother and go for ROG Thunderbird

[maiko]

heres mine

Tube 12au7 for preamp into a Equinox reverb then to a GGG tda20x0 power amp (TDA2050 is in mine)
I also included an effects loop just in case





I also made a circuit to delay the continuity between the amp and speakers to mute the dreaded turn on thump
this is actually pretty loud with a 4ohm speaker load but the output is halved when i hook up to a 8 ohm cab