Hello,

I am sorry but I do not speak German, I have a problem with the kit Reverb that is not producing any reverberation. I have respected the arragement as per your requirement and the voltages are as expected that should mean that I have a correct build/wiring. I have tested the kit with 2 different amplifiers with the same issue. I have a very huge hum when turning the mixer pot that is even covering the music itself. I would like to know if you have a kind of troubleshooting process to check step by step where the problem is coming from?
I have read a question in your forum about if the Reverb can be put before the amp, and someone said yes if there is no distorsion, but myself I always thought that the normal way to connect the Reverb before the amp. So if I understand correctly the guitar is connected to the amp input, the amp output to the Reverb input and the Reverb output to Loudspeaker, right?
Many thanks for your answer.
Regards
Youcef

I always thought that the normal way to connect the Reverb before the amp.

yes, that is the normal way.
Guitar --> Reverb in
Reverb out --> Amp in
Amp Out --> Speaker

So if I understand correctly the guitar is connected to the amp input, the amp output to the Reverb input and the Reverb output to Loudspeaker, right?

This is completely nonsense, but this would be a nice question for an April fool

So if I understand correctly the guitar is connected to the amp input, the amp output to the Reverb input and the Reverb output to Loudspeaker, right?

How dare you build a tube driven device with this state of knowledge?
You are lucky if your amp is still working!
You should educate yourself on the basics of tube electronics and safety rules.

Citing the shop page of the Tube-Reverb: "If you don't understand it than don't build it."

Hello,

I did not say I had connected the Reverb the wrong way, I just saw a reply on the forum that we can connect that way which I agree is a non-sense.
I have build-up several tube amps and I am sure I know what I am doing, I am asking for help not for people blaming me.
Thanks

Hi,

ok, lets summarize: ALL voltages from the schematic are correct, reverb unit is between guitar and amp, guitar to input, output to amp.
The hum changes in response to the MIX potentiometer. So you can trace it back to the dry or to the reverb-path of the circuit.
If only in the wet-path (Mix turned UP):
first guess: is the reverb tank connected in the right direction?
second guess: did you properly clean off the insulating yellowish varnish on the cables of the reverb drivers output-transformer before soldering? Bad connection would result in anything between no-reverb to strange noise.
If only in the dry path: maybe doublecheck the cathode-follower. It is the only thing between in and out in the dry path. Vin should be more or less exactly Vout. You can use the two channels of an oscillograph to compare them.
Another questions: do you have an oscillograph and a sine-generator (computer with soundcard will do) to trace your signals? Then you could step by step check your signal path (200mVpp 1000Hz sine is fine as an input).
Maybe you could provide some high resolution photos of your circuit. A lot of things have been identified in the past via photo-inspection.

To provide some information about yourself (skill-level, experience in tube amps, tech and test equipment) in the beginning could help others to help you.

Cheers,
Andreas

Hi Andreas,

First of all, many thanks for your kind and constructive reply  :topjob:
>>Wet path (mix turned up)
>>>is the reverb tank connected in the right direction?
I have checked and the answer is Yes
>>>did you properly clean off the insulating yellowish varnish
I did not know I had to clean these cables, so I will redo my soldering properly.
>>Dry path
>>>Doublecheck the cathode-follower, Vin should be more or less exactly Vout.
I would like to do that but I do not have an oscillograph.
I will provide you with a high resolution picture asap
I agree with you that presenting himself is a key thing to do.

I will do my homework and keep you updated.

Warm regards
Youcef

Hi,

I did not remember properly: the yellowish-brownish insulation coating was already a problem in a former thread. But it was not on the Reverb-transformers wires, but on the green Heater-wires coming from the power-transformer.
I attached a photo. You can see the coating where the wires are connected to the tubes. Bad Connection - bad heating - bad sound.
This proper problem-diagnosis was made by forum members via inspection of a high res photo, by the way. Here's the according thread:
http://www.tube-town.de/ttforum/index.php/topic,21235.0.html

Cheers
Andreas

For me it sounds like a bad connection and / or a grounding problem.
Pictures would be very helpful.

Regards, Dirk

Hello,

I have followed your advices and I checked my build using an oscilloscope.
I found the problem, it was coming from a bad soldering at the entry tube.
Now it is fixed and the sound of the kit is OUTSTANDING, I love really it............

I still have one thing to ask, the heater voltage is 6.95V, which I think it is too high.
What would you suggest to decrease it to lower value around the expected 6.3V

Many thanks for your support and your kindness.
Cheers
Youcef

Hi,

nice to hear that you found the problem and the reverb is fine now. 6,95V is too high. Maybe you have a more than 230V? Voltage from the wall may vary during the day. You could doublecheck at different times of the day.
Constantly 6,95V  with 230V from the wall would be odd. But you could drop some tenth of a Volt with a resistor in series.

VG
Andreas

I'd tend to two SI-diodes, antiparallel.

Cheers
John

The heater voltage is perfect !!!!
Don't touch it.

Regards, Dirk

Hi,

some sources state a tolerances up to 10% for Vf, some 7%, some 5% in respect to some special types (e.g. http://www.jogis-roehrenbude.de/forum/forum/forum_entry.php?id=44300, http://www.tube-town.de/ttforum/index.php?topic=13606.0, ): 6.95V would be about +10%.

Cheers
Andreas

Hi,

some sources state a tolerances up to 10% for Vf, some 7%, some 5% in respect to some special types (e.g. http://www.jogis-roehrenbude.de/forum/forum/forum_entry.php?id=44300, http://www.tube-town.de/ttforum/index.php?topic=13606.0, ): 6.95V would be about +10%.

Cheers
Andreas

Hallo Andreas:
sorry for this slight addition or the second phrase in Jogi's article: I have tried to translate it

"for indirectly heated tubes...   

7% +/-  without tolerances of the mains transformer...

....additionally a 10% variance of the mains voltage is tolerable. If a 6.3V tube is used with an accumulator, the Voltage may vary from 5.5V to 8V"

So i'd understand the old Siemens Article, that the magical "1000hrs" Lifetime would not be threatend by a heater voltage up to 8V 

Ich glaub wir sehen das enger, als man müsste. Ich hab auf jedenfall noch nie einen durchgebrannten Heizfaden erlebt. Und das Kathodenmaterial fühlt sich bei höherer Wärme auch eher wohler...


Grüße

Jochen

A tolerance of 10% or more is common and no problem. Also a higher heater voltage is in some cases better than a lower voltage.
So the 6,95 V is absolutely perfect. You should learn to read and understand the datasheets correctly and stop to interpret what it might can mean.
I really do not understand this discussions about the heater voltage which appear from time to time, while using the tubes with a plate or screen voltage which exceeds the maximum voltage in a dramatical way is OK for those people. One should focus the important things.

Best regards, Dirk