School me on high gain amps vs classic rock amps
- Thread starter jtcnj
- Start date
Nicely done! We do a few Zeppelin songs, which I quite enjoy!
Dave Sloven
Ambassador of DOOM!
Has anyone given you a simple account of the tech regarding high gain amps?
High gain amps deploy something called 'cascading gain stages' so that gain is built in one tube and then effectively 'cascades' or 'pours' into the next gain tube in the circuit, before going through the effects loop and the phase inverter (sometimes, like in the Peavey 5150/6505 series the effects loop is controlled by a tube, but it does not constitute a gain stage).
For example my Peavey 6534+ works like this:
V1 input -> V6 (crunch) -> V3 (loop) -> V4 (PI) -> power tubes (RHYTHM CHANNEL)
V1 input -> V2 (gain1) -> V5 (gain2) -> V3 (loop) -> V4 (PI) -> power tubes (LEAD CHANNEL)
Other high gain amps have different set ups but this effect of a waterfall that puts pressure on the next stage to increase the gain is the basic tech. If you find that winding the pre-gain up past a certain point creates a mush and doesn't provide more useable gain, you can run a clean boost and/or hotter pickups into V1 instead, which effectively pours more gain into V1. This seems to work for me.
The above layout also shows why it is important to have a more heavy duty valve as V5 in a Peavey 6505 series. Typically you are best off using a Shuguang (Ruby, TAD) or Tesla (JJ) 12AX7 in the V5 slot. The other gain stages are more forgiving. Russian valves aren't good with bigger voltages.
High gain amps deploy something called 'cascading gain stages' so that gain is built in one tube and then effectively 'cascades' or 'pours' into the next gain tube in the circuit, before going through the effects loop and the phase inverter (sometimes, like in the Peavey 5150/6505 series the effects loop is controlled by a tube, but it does not constitute a gain stage).
For example my Peavey 6534+ works like this:
V1 input -> V6 (crunch) -> V3 (loop) -> V4 (PI) -> power tubes (RHYTHM CHANNEL)
V1 input -> V2 (gain1) -> V5 (gain2) -> V3 (loop) -> V4 (PI) -> power tubes (LEAD CHANNEL)
Other high gain amps have different set ups but this effect of a waterfall that puts pressure on the next stage to increase the gain is the basic tech. If you find that winding the pre-gain up past a certain point creates a mush and doesn't provide more useable gain, you can run a clean boost and/or hotter pickups into V1 instead, which effectively pours more gain into V1. This seems to work for me.
The above layout also shows why it is important to have a more heavy duty valve as V5 in a Peavey 6505 series. Typically you are best off using a Shuguang (Ruby, TAD) or Tesla (JJ) 12AX7 in the V5 slot. The other gain stages are more forgiving. Russian valves aren't good with bigger voltages.
chilipeppermaniac
Ambassador of Decibels
67plexi
Ambassador of Amps
Speaking of high gain amps Ken at Trainwreck amps modified a few hundred Marshall's I serviced the west coast amps that Ken
modified until 9/11/2001 then Alaska Air Cargo closed my account. I can't disclose what the modifications are I made a promise
to Ken but the amps did one thing great. High gain most of the big names in metal used Ken's modified Marshall's
modified until 9/11/2001 then Alaska Air Cargo closed my account. I can't disclose what the modifications are I made a promise
to Ken but the amps did one thing great. High gain most of the big names in metal used Ken's modified Marshall's
Whoa!