Hi guys
Quick question about changing the caps on my Sweet Peach KT88.
I love the Sound as it is, but im curious how it could Sound with better caps - Miflex MKP14 0.10uF Poly 600v. How long should the amp rest/decharge before i can start dessembling and soldering the old caps off and new ones in?
Can i change the driver tube 6n1 to a 6n1p without any change?
Thank you in advance!
Best regards
Thomas - Denmark 😄
Quick question about changing the caps on my Sweet Peach KT88.
I love the Sound as it is, but im curious how it could Sound with better caps - Miflex MKP14 0.10uF Poly 600v. How long should the amp rest/decharge before i can start dessembling and soldering the old caps off and new ones in?
Can i change the driver tube 6n1 to a 6n1p without any change?
Thank you in advance!
Best regards
Thomas - Denmark 😄
Beorn87,
Please post a complete and accurate schematic. Answers without such schematic can be suspect.
Safety:
Are there bleeder resistors, or not? Resistance value please; total B+ capacitance (all B+ caps), please; and the B+ operating voltage.
Then we can calculate the time for the B+ to drain to a safe voltage.
If the bleeder resistors are burned out, the connections are bad, etc., then 20to20 is Very Correct, and being properly caustious; I always meter first.
use your meter to measure the B+ voltage until it is a safe value.
Be sure to unplug the amplifier, even with the power off, some have got their arm, hand, etc. on the mains power where it comes to the switch, fuse, etc.
Use your meter (Trust, but Verify).
Safety First!
Prevent the "Surviving Spouse Syndrome".
"Sound":
The sound of different coupling capacitors is dependent on at least the following factors:
1. Even a small amount of DC leakage current will change the bias of next tube's grid.
2. The amount of negative feedback that has the capacitor in the feedback loop:
A. Lots of Global negative feedback with the coupling cap in the loop . . . you may not hear much difference in the sound (negative feedback covers a multitude of sins).
B. Very little (or No) negative feedback with the coupling cap in the feedback loop, (or no feedback loop), will make it easier to hear differences between different coupling caps.
If the coupling caps are a pair, as they are in push pull, then match the capacitance, or you will get more 2nd harmonic distortion from the amplifier.
Mike and the Mechanics: "Can you Hear Me? . . ."
$0.03
Adjusted for inflation
Please post a complete and accurate schematic. Answers without such schematic can be suspect.
Safety:
Are there bleeder resistors, or not? Resistance value please; total B+ capacitance (all B+ caps), please; and the B+ operating voltage.
Then we can calculate the time for the B+ to drain to a safe voltage.
If the bleeder resistors are burned out, the connections are bad, etc., then 20to20 is Very Correct, and being properly caustious; I always meter first.
use your meter to measure the B+ voltage until it is a safe value.
Be sure to unplug the amplifier, even with the power off, some have got their arm, hand, etc. on the mains power where it comes to the switch, fuse, etc.
Use your meter (Trust, but Verify).
Safety First!
Prevent the "Surviving Spouse Syndrome".
"Sound":
The sound of different coupling capacitors is dependent on at least the following factors:
1. Even a small amount of DC leakage current will change the bias of next tube's grid.
2. The amount of negative feedback that has the capacitor in the feedback loop:
A. Lots of Global negative feedback with the coupling cap in the loop . . . you may not hear much difference in the sound (negative feedback covers a multitude of sins).
B. Very little (or No) negative feedback with the coupling cap in the feedback loop, (or no feedback loop), will make it easier to hear differences between different coupling caps.
If the coupling caps are a pair, as they are in push pull, then match the capacitance, or you will get more 2nd harmonic distortion from the amplifier.
Mike and the Mechanics: "Can you Hear Me? . . ."
$0.03
Adjusted for inflation
Last edited:
