What my Ambassador build taught me about the D-lite clean.

[chopstuck]

I had build both the D-lite and the Top Hat Ambassador several months apart. Neither sounded all that good. I wasn't aware of the D-stlye tone stack in the Ambassador and it just sounded like a blackface Bandmaster to me.
Over the years I have been tinkering with my D-lite and trying all the tweaks in Norm's "Tweaked Layout" I really haven' gotten anywhere until....

My 22M resistors were mislabeled from the vendor and in realality were only 2M2. I know I should have checked them.. Grrr. (Where can you get them anyway ?) So I was getting 10x the local nfb, major knucklehead move.
I made up a 40M string of resistors and BAM I had the fatness I was looking for. Still shrill. I rebalanced my PI and rebiased my 6L6's. I then changed out my treble and input cap from SM to ceramic.
There was the tone I had been chasing.

All the work done before was just wasted. How those two little caps could make such a big improvement is beyond me.
I tested them both and found they measured the same on my pretty good cap checker. So I have to mark it up to cap type.

I then applied this knowledge to my Ambassador after noticing the similarity in the preamp.

Again, subbing in two ceramic caps (cobbled together from smaller values), brought the amp alive. Same huge difference. The Ambassador was similar if warmer on clean and with the double tweed Deluxe quasi(AC-30) output stage really doesn't need the PAB switch or OD stage to go dirty. Though I may try PAB at a later date.

Color me suprised that 25 cents worth of parts can hold back these amplifiers.
I have to be more thoughtful of my use of silver mica caps in different amps.

The old domino mica sounds good in my Rocket though.

[groovtubin]

I had build both the D-lite and the Top Hat Ambassador several months apart. Neither sounded all that good. I wasn't aware of the D-stlye tone stack in the Ambassador and it just sounded like a blackface Bandmaster to me.
Over the years I have been tinkering with my D-lite and trying all the tweaks in Norm's "Tweaked Layout" I really haven' gotten anywhere until....

My 22M resistors were mislabeled from the vendor and in realality were only 2M2. I know I should have checked them.. Grrr. (Where can you get them anyway ?) So I was getting 10x the local nfb, major knucklehead move.
I made up a 40M string of resistors and BAM I had the fatness I was looking for. Still shrill. I rebalanced my PI and rebiased my 6L6's. I then changed out my treble and input cap from SM to ceramic.
There was the tone I had been chasing.

All the work done before was just wasted. How those two little caps could make such a big improvement is beyond me.
I tested them both and found they measured the same on my pretty good cap checker. So I have to mark it up to cap type.

I then applied this knowledge to my Ambassador after noticing the similarity in the preamp.

Again, subbing in two ceramic caps (cobbled together from smaller values), brought the amp alive. Same huge difference. The Ambassador was similar if warmer on clean and with the double tweed Deluxe quasi(AC-30) output stage really doesn't need the PAB switch or OD stage to go dirty. Though I may try PAB at a later date.

Color me suprised that 25 cents worth of parts can hold back these amplifiers.
I have to be more thoughtful of my use of silver mica caps in different amps.

The old domino mica sounds good in my Rocket though.

Yeah silver mica SUX in these amps, if you are HARD of hearing, or have a customer who is, have at it, i found that a old domino cap works fantastic in OD entrance HRM! These amps have so much available gain, the ceramic tends to stay more focused under pressure.....i blv silver mica caps were invented after the aliens crashed in N Mexico anyways! lol!

[chopstuck]

Thanks for the tip on the domino!
I will try that too.