To mod red stripe Peavey Bandit preamp or not to mod?

[Steben]

Hi Guys,

What is you opinion on modding the Red Stripe Bandit?
In essence it is a great SS amp. One of the best ever. A couple of elements make this:

- Transtube power amp emulation circuitry. Not a thing of digital stuff whatsoever.
- Good spring reverb
- FX loop, preamp out, power amp in....
- Plenty of power.
- Sturdy reliable amp.
(extra one) - In-the-blues Youtube superman Shane's review on Bandits ....
I mean: https://www.youtube.com/watch?v=Wc4NkZUItOg 

Everything does have a downside. The Bandit's are

- Preamp (both) channels seem to miss something. Is it chime? is it presence? Something...
- No external cab connection or speaker in.
- (to me) some useless sounds in the lead channel. Only the "vintage" voice has some quality.
- Too much standard allround speaker (already swapped wth an Eminence Swamp Thang - great!)
- Even at lowest Transtube settings plenty loud. Again the emulation went that far you really need volume to get the compression.
  Makes me think most humble owners did not appreciate the quality of it (already fixed this one with an extra master control at power amp level - great!)
- g'dmn heavy... emulation of tube amps went far with this one
(extra one) - Not the prettiest amp ever, really dislike the chunky corners

Now the question is: is it a hands off for a classic solid state amp? A speaker swap is not a value downer so that was a great move. But is this thing worth the original circuit? Or are some things interesting to mod?

I've seen someone modding the entire preamp into JFET stages. With a FETZER as input stage. Yet I wonder whether a FETZER does a lot.... I actually haven't found a good way to calculate the original input impedance with the darlington setup....

[thetragichero]

yo dawg have at it. not incredibly desirable or collectible so do what will make you fail in love with it

[teemuk]

IMO, transtube is a more realistic triode emulation than the fetzer. The input impedance with darlington is "high enough" and if you look at it, the transtube preamp is dimensioned for lower impedance of semiconductors to begin with. The whole idea of the design is in ample ratio of asymmetric clipping distortion and bias shifts, not specific device characteristics. Peavey experimented with FETs for transtube circuit but preferred consistency of BJTs over any characteristics FETs could have introduced. So the practical difference is likely minimal.
BTW, the Transtube preamp design also aims for very little clipping distortion to be introduced by the input stage. The gain staging and voicing of the whole overdrive channel is largely derived from their tube-based "Ultra Gain" preamp designs. Transtube is basically a solid-state conversion of that particular circuit design.
Yep, T-Dynamics power amp demonstrates how loud even small amount of output power is through efficient speakers. My 0.5W practice amp, for instance, is definitely way too loud to be cranked in apartment.   

[Steben]

IMO, transtube is a more realistic triode emulation than the fetzer. The input impedance with darlington is "high enough" and if you look at it, the transtube preamp is dimensioned for lower impedance of semiconductors to begin with. The whole idea of the design is in ample ratio of asymmetric clipping distortion and bias shifts, not specific device characteristics. Peavey experimented with FETs for transtube circuit but preferred consistency of BJTs over any characteristics FETs could have introduced. So the practical difference is likely minimal.
BTW, the Transtube preamp design also aims for very little clipping distortion to be introduced by the input stage. The gain staging and voicing of the whole overdrive channel is largely derived from their tube-based "Ultra Gain" preamp designs. Transtube is basically a solid-state conversion of that particular circuit design.
Yep, T-Dynamics power amp demonstrates how loud even small amount of output power is through efficient speakers. My 0.5W practice amp, for instance, is definitely way too loud to be cranked in apartment.   

That's a clear view on it.
In summary what you say is there is little to refurbish tonewise. Yet the addition of an external cab jack unplugging the speaker might still be useful.
I've seen people swapping the opamps.... while in the preamp section there is no opamp and in the power amp section none affect the tone.

[Steben]

Are there any tips about replacing or covering the front panel? The chunky corners aside, the looks of the front panel is what I dislike the most.
Add a thin metal on top?

[GGBB]

Are there any tips about replacing or covering the front panel? The chunky corners aside, the looks of the front panel is what I dislike the most.
Add a thin metal on top?

Sell it and buy the transtube silver stripe version.

[GGBB]

- Preamp (both) channels seem to miss something. Is it chime? is it presence? Something...

Could that be the Swamp Thang? It's know for "taming" top end. (Never used one myself.)

A speaker swap is probably the best way to change the tone of an amp. Not that there's anything wrong with a Swamp Thing, but maybe you might like something else better. Was the chime/presence lacking with the original speaker?

[Steben]

- Preamp (both) channels seem to miss something. Is it chime? is it presence? Something...

Could that be the Swamp Thang? It's know for "taming" top end. (Never used one myself.)

A speaker swap is probably the best way to change the tone of an amp. Not that there's anything wrong with a Swamp Thing, but maybe you might like something else better. Was the chime/presence lacking with the original speaker?

Actually, the sound with the Swamp Thang is really miles ahead of the stock speaker. The stock was too flat perhaps even too bright.
I think of the tone control myself... which might need some tweaking. Since I know difference between tube amps with the same preamp devices and bias can be just as big with just EQ.
Don't get me wrong, it is still a great amp. Especially for SS. I am talking about 1%.

[Steben]

Are there any tips about replacing or covering the front panel? The chunky corners aside, the looks of the front panel is what I dislike the most.
Add a thin metal on top?

Sell it and buy the transtube silver stripe version.

lol 

[GGBB]

Actually, the sound with the Swamp Thang is really miles ahead of the stock speaker.

I don't doubt that - just trying to point out that even though it's miles better, maybe what is missing from the Eminence was present in the stock speaker (which one by the way? my silver stripe transtube bandit has the sheffield). It's really tough to shop around for speakers unless you fork out a lot of dough to buy a few and then sell (at a loss no doubt) the ones you don't keep, but they make a huge difference - not unlike different pickups for guitars.