Building Custom Bass Amp

[staybobo]

Mercury Magnetics Hiwatt Partridge Transformers: OT HI200-O & PT HI200-P.*
Preamp tubes: 5751 & 12AY7.
Driver tubes: 12AX7 & 12AU7.
Power tubes: 6550.
Rectifier: Solid State.
2 Inputs Passive & Active
Optical 3:1 Compressor/Limiter w/switch.
Wattage knob to go from 350 watts to 30 watts.
Master volume per channel.

Channel 1: 4 band Baxandall Eq. & 9 Band Graphic Eq. *- Clean to Moderate breakup
Channel 2: Sunn Bass Coliseum Eq.*& 9 Band Graphic Eq. *- Dirty to Fuzzed out
Effect: Envelope Filter w/Graphic Eq.

Foot pedal: Channel 1/2, Graphic Eq off/on, & Envelope Filter off/on
Speaker Cabinet: 1964 Gibson Titan III Speaker Cabinet For Bass.

[BogeyBass]

Cool dude that is alot of stuff is this a kit or do you plan on laying that all out yourself.

Interested in how your doing the pre and EQ's board? turrents?
350 watts so....6 or 8 power tubes? plate voltage?

sounds like a monster, going to need healthy bias current and one hell of a phase splitter.

cant wait to see this.......

[BassmanPaul]

Interesting. Have you ever built a tube amp before or designed one???

[B-string]

3 graphic EQ's? Really? One on one channel maybe IHMO. I find graphic EQ's more destructive than useful, but it is not my amp

[JGR]

Go with Heyboer instead of Mercury unless you get a discount on MM.

[B-string]

BTW the output trans you listed is a 200 watt transformer. It won't due 350 watts.

[B-string]

Originally Posted by JGR

Go with Heyboer instead of Mercury unless you get a discount on MM.

Have you tried http://www.magneticcomponents.net/ ? I just installed one of their OTs in a Marshall 6100. It turned out to be not only a good replacement but a tone improvement as well. Creamy OD, more open lows and sweeter highs.
A "SVT' or 400/400+ OT would be a special order (300 watt plus) but they do special orders all the time and more reasonable than MM?

[Bassmec]

Originally Posted by B-string

BTW the output trans you listed is a 200 watt transformer. It won't due 350 watts.

But then again he didn't say how many 6550 tubes he has in his design
So we don't know a lot, perhaps it's such much:

but starved plate.

[B-string]

Originally Posted by BassmanPaul

Interesting. Have you ever built a tube amp before or designed one???

My bet is no, but I have been wrong before.

[staybobo]

No I haven't built an amp before.

Mercury Magnetics Hiwatt Partridge Transformers: OT HI200-O & PT HI200-P & Mosfet
Preamp tubes: 5751 & 12AY7.
Driver tubes: 12AX7 & 12AU7.
Power tubes: 5 6550.
Rectifier: Solid State.
2 Inputs Passive & Active
Optical 3:1 Compressor/Limiter w/switch.
Wattage knob to go from 200W Tubes/450W Mosfet to 30W
Master volume per channel.

Channel 1: Tubes 4 band Baxandall Eq. & Switchable Off/On 9 Band Graphic Eq. Clean to Moderate breakup @ 200w.
Channel 2: Mosfet Sunn Bass Coliseum Eq. Dirty to Fuzzed out @ 450W.

Foot pedal: Channel 1/2 & Compressor/Limiter.

Speaker Cabinet: 1964 Gibson Titan III Speaker Cabinet For Bass.

[BassmanPaul]

The voltage required by a 350W amp is lethal and needs special measures to be taken. Even after 50+ years of working with tube electronics this is a project I would think more than twice about attempting.

[BassmanPaul]

Originally Posted by staybobo

No I haven't built an amp before.

Then if you attempt this you are in danger of losing your life!!! I just can't emphasize that enough.

[JGR]

Originally Posted by B-string

Have you tried http://www.magneticcomponents.net/ ? I just installed one of their OTs in a Marshall 6100. It turned out to be not only a good replacement but a tone improvement as well. Creamy OD, more open lows and sweeter highs.
A "SVT' or 400/400+ OT would be a special order (300 watt plus) but they do special orders all the time and more reasonable than MM?

They do indeed make great stuff; I have used them for guitar as well. I inquired about an SVT style a few years ago and they wouldn't do it. Heyboer are great and very well priced. I've got five custom chassis waiting for a big amp, and the design is done, but as Bassmanpaul said, it's a huge undertaking.

To the OP, if you haven't built an amp before - make that several - DON'T start with something this complex and dangerous. .

[staybobo]

What style output and power transformer should I use?

Tube/Mosfet bass amp
Preamp tubes: 3 5751 & 2 12AY7.
Driver tubes: 3 12AX7 & 1 12AU7.
Power tubes: 4 6550.
Rectifier: Solid State.
2 Inputs Passive & Active
Optical 3:1 Compressor/Limiter w/switch.
Wattage knob to go from 200W Tubes/450W Mosfet to 30W
Master volume per channel.

Channel 1: Tubes 4 band Baxandall Eq. Clean to Moderate breakup @ 200w.
Channel 2: Mosfet Sunn Bass Coliseum Eq. Dirty to Fuzzed out @ 450W.

Foot pedal: Channel 1/2 & Compressor/Limiter.

Speaker Cabinet: 1964 Gibson Titan III Speaker Cabinet For Bass.