If you only upgrade tubes and keep everything else, power increase, *if* any, will be nil.
If you also change the PT , now you upgraded , say, 66% of your amp, keping a now underrated OT to behave as a bottleneck, limiting any improvememt your big$$ spent can potentially bring.
Personally I'd either leave everything as-sis *or* uograde everything, which in practice amounts to build a new amp (you are doing that anyway).
Halfway solutions are just that, halfway.
IMHO, of course.
If you also change the PT , now you upgraded , say, 66% of your amp, keping a now underrated OT to behave as a bottleneck, limiting any improvememt your big$$ spent can potentially bring.
Personally I'd either leave everything as-sis *or* uograde everything, which in practice amounts to build a new amp (you are doing that anyway).
Halfway solutions are just that, halfway.
IMHO, of course.
I try to keep that point in mind. That assumes the design was balanced and optimized to begin with, generally true for economical designs. My expectations are reasonable, and I haven't even decided what to do yet. KT120's are probably too much for the Super Twin or the Peavey Tour VB-2.
Done carefully the SVT might reap some reliability benefits but its printed circuits are more difficult to modify. The Sound City's Partridge transformers look like 200 watt transformers and it's going to be a complete build with new turret boards and new preamp design anyway, so it might be a reasonable candidate. In their day, there just weren't tubes like the KT120. Way too soon to tell, I don't have plans just sharing my conjecture. Just thinking thru some ossible steps, next starting to think about how to economically add a supplemental power supply to raise B+ witout having to scrap the stock transformer(s).
Done carefully the SVT might reap some reliability benefits but its printed circuits are more difficult to modify. The Sound City's Partridge transformers look like 200 watt transformers and it's going to be a complete build with new turret boards and new preamp design anyway, so it might be a reasonable candidate. In their day, there just weren't tubes like the KT120. Way too soon to tell, I don't have plans just sharing my conjecture. Just thinking thru some ossible steps, next starting to think about how to economically add a supplemental power supply to raise B+ witout having to scrap the stock transformer(s).
Now the Peavey Tour VB-2 is running with the Trace Elliot V6/V8 output transformer which is good for at least 400 watts and has twice the iron of the original VB-2 output trans. The stock power transformer looks pretty oversize and VB is pretty high, so I imagine if I added to the main filter caps then upgrading from 6 EL34 to 6 KT88 would provide some benefit (assuming proper bias and maybe some resistor wattage upgrades) but that doesn't necessarily mean it will sound any better. And I just paid for those 6 new EL34's so it's not likely to happen for a long time.
If you can't remove the heat from the oil then you gain no benefit at oil (oops all), and just make a bigger hotter problem.
A more plausible technique for an existing Tx, or one you have no control over purchasing, is to remove a few laminations on either side and replace with copper strip and then transfer from the copper strip tabs (eg. a phase change tube to a finned heatsink external to the chassis).
A more plausible technique for an existing Tx, or one you have no control over purchasing, is to remove a few laminations on either side and replace with copper strip and then transfer from the copper strip tabs (eg. a phase change tube to a finned heatsink external to the chassis).
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One "trick" for increasing output power I've seen used successfully, is to use the next higher tap on the output transformer, to lower the input impedance.
Bob Carver used it on a Citation II, On the Tronolla website? someone used it on an Eico ST70 with good results.
Basically you use the 16 Ohm tap for the 8,8 for the 4 etc...
As far as heat control,I've seen some transformers with the end laminations being extended to create large fins(on a battery charger)
for heat radiation.
Bob Carver used it on a Citation II, On the Tronolla website? someone used it on an Eico ST70 with good results.
Basically you use the 16 Ohm tap for the 8,8 for the 4 etc...
As far as heat control,I've seen some transformers with the end laminations being extended to create large fins(on a battery charger)
for heat radiation.
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