[LP]

Hello everybody, this is my first post here.
My name is Lionel, from France, i'm 38 years old.
I build pedals for few years, and have electronic and electricity  basis
Also, my english is not terrible 
I come here because i have a little problem with my tube reverb. I only get 210v on B3, and all DC voltages are 20% lower throughout the circuit (6.3 VAC is good).
I connected the purple wire of the primary of the OT (sector 230v), and the resistor R6 8K2.
If I put the R6 resistor 1K, I get a voltage >300v on B3.
Do I have to adjust R6 until I get the right values?
I also have a hissss when I raise the tone. Is it possible to reduce it?
Thank you.

[LP]

*PT not OT, sorry...

[smid]

Hi Lionel,

I would first check the cathode-voltages and resistors. Maybe a value is wrong and e.g. your 6V6 draws a lot of current in idle and makes the voltage drop.
Regarding the hiss: a certain amount is normal, since the reverb-recovery-stage ist delicate and tends to collect some dirt. You should hear it also when you turn the mix-pot from dry to wet. Normally the dry path is very clean. When you turn the mix to wet you start to add the reverb and all the hiss and hum the recovery stage collects. You can experiment with shielding, position/orientation of the reverb-pan, type of tube etc. I personally never got completely rid, but could reduce it always to a tolerable amount (less than the dirt from the single-coil pickups). It also helps to turn up the dwell (just before it starts to overdrive the reverb) and turn down the mix.
Also make sure that all your grounds are well made. the contact to the chassis should be made 100%. Sand the chassis at the connection point a little to eliminate all surface-contact issues.

I hope this helps,
Andreas

[LP]

Hello Andreas, thanks for your answer.
I'am talking about the tube town tube reverb kit, there is no 6v6 tube, it is replaced by an ecc833.
The PT is wiring on a board in order to convert AC current on DC current.
Before B3 (DC out) of this board, i have the choice between 2 resistors (on tube town schematics), 1k (for push pull) and 8k2 (for single ended).
With the 8k2, for single ended circuit, i obtain only 210v DC instead of the 260v. With the 1K resistor, DC value is >300V
I don't understand where is the problem 
Must i buy others resistors values and make test in order to obtain 260v?

[LP]

oh I may have understood. If i put the 1k resistor, can the DC current drop to 260v on charge (with reverb circuit connected)? But i don’t undetstand because oit is a single ended circuit, I’m supposed to put the 8k2 resistor...
And i don't want to burn it 

[stephan61]

Hi Lionel,
Thats indeed what Andreas pointed out, there might be too much voltage drop between B2 and B3 due to current draw caused by a wrong resistor value somewhere in the circuit.  Double check of all parts may be helpful.

regards Stephan

[smid]

Hi Lionel,

I just had a look at the photos from the project page. There ist looks like they used the 1k.  Do you get the >300V only with the power-supply and no circuit connected ? That would be normal, since there is no load on the power-supply.  Connect the circuit with tubes, you should get a significant drop.

Andreas

[LP]

It is that you make think to me because of your previous post, when i put the 1k resistor, i didn't wire the circuit, because i'm worrying by the >300vdc current.
I didn’t think to check the tube town project photos 
Tomorrow, i go to put a 1k resistor (if i found one another in 2w, i lost mine  >: ).
But sure it'll works fine.
Thanks a lot andreas 

[LP]

Hello,
I put the 1k r6 resistor, it works perfectly, i obtain 275v on B3, and no hiss

The time of the reverb is good, but however, i not find it deep enought, i would like mixer let only the reverb signal go out when i put it at 12.
 How can i modify it for that?

Thanks.

[smid]

You could try a larger mix pot, like 500k, that might separate the signals a bit more, but due to the general architecture there will always be a small amount of dry signal come through the pot.
You can make a test and shunt the dry signal to ground, to estimate, wether the pure reverberated signal sounds the way you like.

Andreas

[LP]

Hello Andreas,
I think also to remove the 3 «upgrade» resistors (in red on the upgrade schematic), its seems to down reverb signal, and ecc833 voltage.
What do you think of this?
Thanks.
Lionel.

[smid]

You can lower R19 to allow the El844 to be (over-)driven harder. You can experiment with different values. I would keep R20 and R21.

Andreas

[LP]

Hi Andreas,
I have shunt the 220k resistor and reverb sounds great.
Lionel.

[smid]

 

[LP]

Hello, i also put a 8ab3c1b tank, and reverb is more expressive