Compression in a Rocket? (Clean vol almost = dirty vol)

[sniffyduke]

Crap, thats what mine does now. It was a total mistake.
The build was a disaster, Mark Knows LOL

But you can hang on a note forever...

I have a 300V PT and NOS CC resistors which have totally off values LOL

[M Fowler]

Mike Its looking good red velvet and all.

[sniffyduke]

Its a disaster ROFL

But if you want compression, im your man : )

[M Fowler]

Mike what value screen resistors did you use?

[sniffyduke]

1k 6.5watts

[sniffyduke]

See

There is hardly zero break up with a strat, but with a Les Paul its like that Express youtube clip, you can hold the note with hardly any feedback for as long as you want. @_@

[Structo]

What is the purpose of the red felt?

[strat_addict]

See

There is hardly zero break up with a strat, but with a Les Paul its like that Express youtube clip, you can hold the note with hardly any feedback for as long as you want. @_@

That would be no good for me, all I use are strats with the occasional tele.

[sniffyduke]

What is the purpose of the red felt?

It looked cool : )

[strat_addict]

Alright, I've been thinking alot and theres alot of stuff I want to change with the Rocket. By the end, it will be a totally different machine. Here's my plans so far:

Rocket 1x12 combo (probably from Mather custom cabs)
Alnico Gold speaker
Fat switch (based on the old fenders)
Fast/Gradual switch
Use some of the ideas in this topic to compress my overdriven tone
Mix a KT66 with 2 EL84's for the power tubes (this would give me about 40 watts; I'm not sure how well this would work electronically but sonically I think it should work well)

What are some ways I could keep each stage that goes into distortion no more than 6-9db into distortion? I've heard this makes a better, smoother overdriven tone. And is a low pass filter in or after the amp a good idea and how well would series grid resistors work?

The stuff in red is some stuff I read that is supposed to give me a better, smother, less fizzier overdrive.

[passfan]

Actually, too hot bias won't help you as it'll tend towards class A rather than AB. Once you get into true class A the power drawn will be constant (of course this implies prior to power tube distortion), so you won't get much sag and therefore any power supply compression.

What you want is the power supply to start bogging down as soon as you get into distortion, so that the volume will effectively drop, bringing it down to closer to the clean volume.

What you probably want to do is to get the preamp on the verge of clipping, so you're in the 'clean' zone. Then adjust the input into the power tubes to get as high an output as you can without the current drawn suddenly beginning to increase rapidly. If you can get the gain staged like this then as soon as you get into overdrive you'll force the output tubes to draw more current and pull the voltages down.

You could very easily experiment with this by adding a PPIMV (post-phase inverter master volume) temporarily and the sag resistor and then tweaking to taste. It would probably be quicker than setting up a SPICE simulation or taking measurements and experimenting with resistor values to get the gain staged just right.

I think I'm close to achieving this state. I used a 300 - 0 - 300 PT with a 130 ohm 25 watt coming off a 5u4g rectifier tube through the usual trainwreck filter string, kept the choke for now. Voltage on the plates is 302 volts, screens are at 300 with 1K resistors. Lowered the bias down with 75 ohm resistor which puts it around 9.86 volts. I am using a 12ay7 for the PI because it sounds clearer. For some reason I lost some treble response, perhaps due to the power supply mods ??? I don't know. When I get my gain just right, which is about 1:00 I can do the clean to mean right around 8 or 9 and full on. It's clean by 8 . This sounds really sweet but with my heaters referencing a low cathode voltage I get a very small amount of hum. I'm not so sure it's not coming from my B+ being drug down either. I'll tell you this, this thing sounds sweet. Everyone that hears it loves it. My V has a single coil P90 in the neck and it chimes like a filtertron. Everything runs hotter than normal.

[strat_addict]

Actually, too hot bias won't help you as it'll tend towards class A rather than AB. Once you get into true class A the power drawn will be constant (of course this implies prior to power tube distortion), so you won't get much sag and therefore any power supply compression.

What you want is the power supply to start bogging down as soon as you get into distortion, so that the volume will effectively drop, bringing it down to closer to the clean volume.

What you probably want to do is to get the preamp on the verge of clipping, so you're in the 'clean' zone. Then adjust the input into the power tubes to get as high an output as you can without the current drawn suddenly beginning to increase rapidly. If you can get the gain staged like this then as soon as you get into overdrive you'll force the output tubes to draw more current and pull the voltages down.

You could very easily experiment with this by adding a PPIMV (post-phase inverter master volume) temporarily and the sag resistor and then tweaking to taste. It would probably be quicker than setting up a SPICE simulation or taking measurements and experimenting with resistor values to get the gain staged just right.

I think I'm close to achieving this state. I used a 300 - 0 - 300 PT with a 130 ohm 25 watt coming off a 5u4g rectifier tube through the usual trainwreck filter string, kept the choke for now. Voltage on the plates is 302 volts, screens are at 300 with 1K resistors. Lowered the bias down with 75 ohm resistor which puts it around 9.86 volts. I am using a 12ay7 for the PI because it sounds clearer. For some reason I lost some treble response, perhaps due to the power supply mods ??? I don't know. When I get my gain just right, which is about 1:00 I can do the clean to mean right around 8 or 9 and full on. It's clean by 8 . This sounds really sweet but with my heaters referencing a low cathode voltage I get a very small amount of hum. I'm not so sure it's not coming from my B+ being drug down either. I'll tell you this, this thing sounds sweet. Everyone that hears it loves it. My V has a single coil P90 in the neck and it chimes like a filtertron. Everything runs hotter than normal.

Besides the hum and treble loss, does any other part of the sound change?

[passfan]

Actually, too hot bias won't help you as it'll tend towards class A rather than AB. Once you get into true class A the power drawn will be constant (of course this implies prior to power tube distortion), so you won't get much sag and therefore any power supply compression.

What you want is the power supply to start bogging down as soon as you get into distortion, so that the volume will effectively drop, bringing it down to closer to the clean volume.

What you probably want to do is to get the preamp on the verge of clipping, so you're in the 'clean' zone. Then adjust the input into the power tubes to get as high an output as you can without the current drawn suddenly beginning to increase rapidly. If you can get the gain staged like this then as soon as you get into overdrive you'll force the output tubes to draw more current and pull the voltages down.

You could very easily experiment with this by adding a PPIMV (post-phase inverter master volume) temporarily and the sag resistor and then tweaking to taste. It would probably be quicker than setting up a SPICE simulation or taking measurements and experimenting with resistor values to get the gain staged just right.

I think I'm close to achieving this state. I used a 300 - 0 - 300 PT with a 130 ohm 25 watt coming off a 5u4g rectifier tube through the usual trainwreck filter string, kept the choke for now. Voltage on the plates is 302 volts, screens are at 300 with 1K resistors. Lowered the bias down with 75 ohm resistor which puts it around 9.86 volts. I am using a 12ay7 for the PI because it sounds clearer. For some reason I lost some treble response, perhaps due to the power supply mods ??? I don't know. When I get my gain just right, which is about 1:00 I can do the clean to mean right around 8 or 9 and full on. It's clean by 8 . This sounds really sweet but with my heaters referencing a low cathode voltage I get a very small amount of hum. I'm not so sure it's not coming from my B+ being drug down either. I'll tell you this, this thing sounds sweet. Everyone that hears it loves it. My V has a single coil P90 in the neck and it chimes like a filtertron. Everything runs hotter than normal.

Besides the hum and treble loss, does any other part of the sound change?

It seems to have lost that fizz when you pushed on past the breakup of my original rocket. Perhaps a little bit more sustain. It's hard for me to crank it with the wife and grandaughter running around all day. I'll get a chance sometime next week but I like it a lot better than the old version. I've yet to try out a ppimv and fine tune the power supply sag. It's really smooth when it breaks up and mind you I've been swapping tubes thru it all day. I'm running 2 7025's and a 12ay7 with 4 mismatched Saratovs on the output.

[strat_addict]

I think I'm close to achieving this state. I used a 300 - 0 - 300 PT with a 130 ohm 25 watt coming off a 5u4g rectifier tube through the usual trainwreck filter string, kept the choke for now. Voltage on the plates is 302 volts, screens are at 300 with 1K resistors. Lowered the bias down with 75 ohm resistor which puts it around 9.86 volts. I am using a 12ay7 for the PI because it sounds clearer. For some reason I lost some treble response, perhaps due to the power supply mods ??? I don't know. When I get my gain just right, which is about 1:00 I can do the clean to mean right around 8 or 9 and full on. It's clean by 8 . This sounds really sweet but with my heaters referencing a low cathode voltage I get a very small amount of hum. I'm not so sure it's not coming from my B+ being drug down either. I'll tell you this, this thing sounds sweet. Everyone that hears it loves it. My V has a single coil P90 in the neck and it chimes like a filtertron. Everything runs hotter than normal.

Besides the hum and treble loss, does any other part of the sound change?

It seems to have lost that fizz when you pushed on past the breakup of my original rocket. Perhaps a little bit more sustain. It's hard for me to crank it with the wife and grandaughter running around all day. I'll get a chance sometime next week but I like it a lot better than the old version. I've yet to try out a ppimv and fine tune the power supply sag. It's really smooth when it breaks up and mind you I've been swapping tubes thru it all day. I'm running 2 7025's and a 12ay7 with 4 mismatched Saratovs on the output.

Does it get a fair amount of gain with the 12AY7's and a Strat?

[passfan]

Besides the hum and treble loss, does any other part of the sound change?

It seems to have lost that fizz when you pushed on past the breakup of my original rocket. Perhaps a little bit more sustain. It's hard for me to crank it with the wife and grandaughter running around all day. I'll get a chance sometime next week but I like it a lot better than the old version. I've yet to try out a ppimv and fine tune the power supply sag. It's really smooth when it breaks up and mind you I've been swapping tubes thru it all day. I'm running 2 7025's and a 12ay7 with 4 mismatched Saratovs on the output.

Does it get a fair amount of gain with the 12AY7's and a Strat?

Hard for me to help out there ; I don't own a strat. In between 11:00 and 1:00 I get a nice clean compressed type of chord structure. It's not quite into breakup yet but you can tell it's leaving clean. After 1:00 it's there and single notes and bends have distortion (no fizz) and from there on up it just tends to compress more with no apparent volume increase. That is on my bridge pickup, which is a 59 classic humbucker, and turning down to around 8 makes it clean back up again, regardless of where the amp is set with hardly any drop in volume. All this is subtle and not overly pronounced. It gets a little bit rougher around the edges with a 12ax7 in the PI.

My neck pickup is a single coil P90 in the neck position but I don't play it all the way I run it on 6 or 7 at the guitar volume. It gets bassy at 10 like a neck pickup would , but at 6 or 7 it is creamy and chimey as all getup and sounds to die for when fingerpicking leads.. I'm sure you could get close rather quickly just by popping a 130 ohms between your rectifier and first B+ cap and adding 25 ohms in series with your 50 ohms cath resistor. I'm also runnung 1k on my screens which I do anyway, I didn't have to change that.

If I can get into my buds studio I will try to make some clips to post but I can't promise anything. I may need some advice on how to convert them down.