Need suggestions for dull sound
Moderators: pompeiisneaks, Colossal
Re: Need suggestions for dull sound
I still say V1 is bad. Your cathode voltage is probably about 20% low. Not saying that is your main issue, but everything matters....
Link
OK, Here is a link to my build with all the pics. Nothing fancy, just pics.
It has 2 channels, Fender clean and Dumble clean, Deep, Mid Boost, PAB switches. No Hrm. V1 is typical fender ckt. It sounds great.
Rut
http://www.cooltoneamps.com/rcc/dumbel.aspx
It has 2 channels, Fender clean and Dumble clean, Deep, Mid Boost, PAB switches. No Hrm. V1 is typical fender ckt. It sounds great.
Rut
http://www.cooltoneamps.com/rcc/dumbel.aspx
Re: Link
rutledj wrote:OK, Here is a link to my build with all the pics. Nothing fancy, just pics.
It has 2 channels, Fender clean and Dumble clean, Deep, Mid Boost, PAB switches. No Hrm. V1 is typical fender ckt. It sounds great.
Rut
http://www.cooltoneamps.com/rcc/dumbel.aspx
It appears that you used 1/2 watt metal films on the plate load resistors. I've found that the Vishay Dale RN65's have a more open tone, more alive.
I also see a silver mica cap but I can't quite see what it's used for. As bright caps and tone caps that can suck the life out.
What's the capacitance of the shielded wire? Some higher capacitance wire can dull the amp.
I agree with trying another tube in the Dumble clean. The cathode voltage seems a tad low. Adjust the bias no more than 35ma.
Good luck
Re: Need suggestions for dull sound
I noticed a bunch of things I would change.
1) Use PS Orange Drops (try .02 uf on CL2 not .01 MPP)
2) Use 24MM 1M volume pots. The smaller ones suck tone. If possible use 24MM for the treble pot and OD pots too.
3) The Presence pot is wired wrong (if you didn't tie the legs together), it is a varibale resistor.
4) OD drive is 100Kb unless HRM amp
5) OD Drive has a 100K resistor feeding it, not 150K. Especially bad since you have 250K pot
6) Check V3 cap sizes. Should be .01uf on the 220K plate and .005uf on 150K plate
7) Pre OD network has a 220K resistor feeding 100K trimmer. Do I see a 100K there?? Must be at least 180K.
8 ) Snubbers should start out at 270pf. Raise the 150K grid stopper if too bright (180K)
Why is there a ceramic disc to ground on the clean master? That will bleed highs to ground.
1) Use PS Orange Drops (try .02 uf on CL2 not .01 MPP)
2) Use 24MM 1M volume pots. The smaller ones suck tone. If possible use 24MM for the treble pot and OD pots too.
3) The Presence pot is wired wrong (if you didn't tie the legs together), it is a varibale resistor.
4) OD drive is 100Kb unless HRM amp
5) OD Drive has a 100K resistor feeding it, not 150K. Especially bad since you have 250K pot
6) Check V3 cap sizes. Should be .01uf on the 220K plate and .005uf on 150K plate
7) Pre OD network has a 220K resistor feeding 100K trimmer. Do I see a 100K there?? Must be at least 180K.
8 ) Snubbers should start out at 270pf. Raise the 150K grid stopper if too bright (180K)
Why is there a ceramic disc to ground on the clean master? That will bleed highs to ground.