I have been fooling with my Champ 600 and I've compared it to my 5F1 clone (was a Kendrick Roughneck).
http://ampgarage.com/forum/viewtopic.php?t=26589
One thing I've found with the 5F1 clone is that I've changed coupling caps valves, speakers, and output transformers and yet there is alway this sameness about the tone of the amp. The only thing that is the same in this amp is the power transformer, the wiring, the circuit card and the resistors.
Okay, this is the bit that gets me, the Champ 600 has had the tone controls removed, and has a larger output transformer (both are Mercury Magnetics) the amp is quite Champ like apart from the cathode cap across the second stage, but the amps sound and feel quite different to play.
Any thoughts of suggestions on this one?
The effect of power supplies on amp tone?
Moderators: pompeiisneaks, Colossal
The effect of power supplies on amp tone?
Yours Sincerely
Mark Abbott
Mark Abbott
-
Stevem
- Posts: 4576
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: The effect of power supplies on amp tone?
You've answered your own question if you ask me!
A bigger OT especially in a SE amp goes down below 150 hz better normally no less when driven hard and saturates less also!
The power supply/ PT current output needs in a Class A amp stays very flat so you can't pin down a whole lot of tonal difference to that detail.
A bigger OT especially in a SE amp goes down below 150 hz better normally no less when driven hard and saturates less also!
The power supply/ PT current output needs in a Class A amp stays very flat so you can't pin down a whole lot of tonal difference to that detail.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: The effect of power supplies on amp tone?
The power supply of a class A amp doesn't sit flat when a signal is applied as it would at it's idle voltage. The rail actually increases as the signal increases. This stops when the amp clips at that point the rail starts to go down so sag starts to play a part.
The other factor that is sometimes talked about is the small filter caps coupled with the 10K and 22K series power supply resistors on the screen and pre-amp, the idea being that the screen current will pull down the rail voltage to the pre-amp down causing compression. I can't say I've noticed this with a 6V6, but I have had an 6L6 in the amp and I did notice compression. It sounded like the notes attack was cut off, which wasn't that wonderful.
Of course all of this doesn't address that I hear a sameness in the amp despite the speaker or output transformer used in the amp. Needless to say some output transformers do have more bass and some speakers are brighter (or fatter sounding in the case of Weber Silver Ten). That taken into account the Kendrick 5F1 clone (more or less 5F1 circuit with Jupiter REDs [they sound good cause they are red, I didn't hear any difference between caps in the Champ and I used a recorded source] Mercury Mag fat stack O/P txer and Silver Ten) still has it same character.
I will have to shelve this for a month, but I do want to explore this further, it's what all builder should strive for to build amps that have their sound.
The other factor that is sometimes talked about is the small filter caps coupled with the 10K and 22K series power supply resistors on the screen and pre-amp, the idea being that the screen current will pull down the rail voltage to the pre-amp down causing compression. I can't say I've noticed this with a 6V6, but I have had an 6L6 in the amp and I did notice compression. It sounded like the notes attack was cut off, which wasn't that wonderful.
Of course all of this doesn't address that I hear a sameness in the amp despite the speaker or output transformer used in the amp. Needless to say some output transformers do have more bass and some speakers are brighter (or fatter sounding in the case of Weber Silver Ten). That taken into account the Kendrick 5F1 clone (more or less 5F1 circuit with Jupiter REDs [they sound good cause they are red, I didn't hear any difference between caps in the Champ and I used a recorded source] Mercury Mag fat stack O/P txer and Silver Ten) still has it same character.
I will have to shelve this for a month, but I do want to explore this further, it's what all builder should strive for to build amps that have their sound.
Yours Sincerely
Mark Abbott
Mark Abbott