[danieleb]

Hi,
I have a problem with my TT reverb, when I turn mix to 0 (dry sound) it's very silent, no noise, but when I turn mix over 4 a noise is udible and on 10 it's very audible.

Tone open increase the noise (it's on the mid and hight freq)

Dwell doesn't change it

To reduce a little the noise I put the tank on the back of the case (more distant from the transformer), if it's out of the case the noise is very little, what can I try?

ps
turning the tank 180° is worst in my case, with RCAs on the front side the noise is more.
I mounted two shield on the 2 ECC and I try a cup on the transformer.

Thanks for help me and sorry for my english

[volvodidi]

Hi Daniel,
i think it is not a good idea to fix the wires parallel with cabelstrips.
Look at the pictures on the project site.
Dieter

[danieleb]

Hi Dieter, thanks
I have grouped the cable after the reading this:

however I did not notice differences, all the noise depends on the position of the tank, if I disconnect the output of the tank the noise disappears, but with the input disconnected and the output connected the noise remains

[danieleb]

The tank must be connected at the chassi or ground?

[Athlord]

The tank must be connected at the chassi or ground?

Chassi must be Grounded = ground

[danieleb]

you mean the chassi of the tank also?
Now it's connected only by the RCAs, the bottom of the tank is on the wood of the case, I have to add a cable or it is better to shield the inside of the case?

Thanks Athlord

[Holzdruide]

Hi

Look at 5. Letter - Connector Input Output - Insulated / Not Insulated Configuration

Franz

[danieleb]

Hi Franz, thanks!
I mounted the medium one: 8AB2A1B

short
in 8ohm - grounded
out 2.250ohm - grounded
medium
no lock
open side down

So I think I don't need another ground, the RCAs are connected to the ground of the chassi

[Athlord]

you mean the chassi of the tank also?
Now it's connected only by the RCAs, the bottom of the tank is on the wood of the case, I have to add a cable or it is better to shield the inside of the case?

Thanks Athlord

the chassi of the Reverb is typically connected to one of the two RCA connectors.
Therefor an extra grounding of the chassi is not necessary.
If you do this, then there could be a ground loop and hum.

[danieleb]

Ok, the connections are right, only the two RCAs between chassi and Tank, I can't think of anything else to reduce interference, maybe a thiker shielding on the trasformer?
Other TT reverbs have this noise?
I noticed also bringing it close to marshall's transformer (putting it on the transformer's side of the head) it increase the noise

[Athlord]

Other TT reverbs have this noise?

No.
It is not a Problem of the TT-Reverb!
Please check your building again,
or ask someone who is familiar with tube-amp.
regards
Jürgen

[Dirk]

Hallo,

there are no know problems with the TT Reverb. It works without any noise and hum when it is build correctly.
I am pretty sure that you have a mistake in your build so please check the grounding and make sure that you don't have a ground loop somewhere.
Don't wast your time with extra shielding and other things like that. Make sure that the grounding is correctly and than you won't have a problem.

By the way on the picture it looks like that one of the resistors which are soldered to the EL84 socket has a connection to the chassis. Please check.

Best regards, Dirk

[danieleb]

Thanks!
The two resistors from the 6VAC are on one side grounded to the screw whit the other ground cables and on the other isulated with heat shrink tubing.
With the multimeter I read 6.6V between the two green cables, now I'll check the others

[danieleb]

B3: 255V

V2:
pin 8 : 2,5V
pin 6 :115 before R4 135
pin 1 :120
pin 3 :2,7

V3
pin 3 : 8,3

V1:
pin 8 :1,26
pin 6 :168
pin 1 :255
pin 3 :128

I think them are correct

[danieleb]

In the chassi I have 2 screws for the ground, one for the main input and one to the others components:
-PSU ground
-RCAs ground (RCAs ground are connected one to the other and with the transformer)
-PCB Ground
-Jacks ground (input, output and footswitch connected toghether)
-two resistors for the heater

Ground for the dwell pot is from pcb near R11