Tube-Town Forum
Technik => Tech-Talk TT-Projekte => Thema gestartet von: flemmingsa am 11.09.2015 22:57
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Hi
I am building the LNDverb standalone version. I have made a test build using a stompbox chassis, so Grounding is not the best yet and a fair bit of noise is present. This Will be resolved later.
However, I have this problem:
When the reverb is connected to an amp i get a Loud and clear spring reverb boing when tapping the tank. When connecting a guitar i Can only get a very faint reverb effect if i turn mix and dwell All the way up.
The LNDverb is powered with a vpump and, for now, an atx psu is providing 12vdc.
I am using a Belton reverb tank i had lying around.
Andy idea what could cause this?
Flemming
DK
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Looks like you don't get signal to the pan and bypass... Maybe a short connection somewhere that bleeds your signal to ground. Check the jacks and if there is any wire touching ground where it is not supposed to do so.
Good luck
LöD
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Thanks for the reply. I will check.
I have full dry guitar signal. It is just the effect that is very faint.
Flemming
Dk
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Hi,
Witch exact type of reverb tank is used? Maybe it has differing impedance.
Greets
Stefan
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Hi
The tank is: Belton BS2EB2C1B
Flemming
DK
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Hi Flemming,
you have the wrong reverb tank. Look at the input impedance: afaik you need a 2AB2C1B-type.
Volka
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Oh, that makes sense... Didn't think of that...
Unfortunately, i think i fried some components in the process. So i guess i'll order the correct tank and start troubleshooting components.
Thanks.
Flemming
Dk
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Is it likely that a tank with the wrong impedance could have damaged some components?
Flemming
DK
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Hi,
if there are damaged components,
there is an other problem, but it´s not the Reverbtank.
Please post good Pictures of your Build.
regards
Jürgen
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Hi
Getting back to this project after a long break...
I mounted everything in a chassis and started troubleshooting.
Vpump is working, but no reverb.
Voltages at LNDs are 0.3vdc, 13vdc and 0.3vdc. So here is a problem.
R14 gets very hot and has a reading of 32.7vdc
Any suggestions?
Flemming
DK
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Anyone?
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As there is no schematic available of the LNDVerb kit, all one could do is guess. It seems that you have a short or a very low resistance ground somewhere, so R14 is dropping all of your B+ voltage. Did you make sure that no part of the circuit is touching the chassis?
Good luck,
-Thorsten
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Tested today and R14 actually smoked!! So I guess I should try replacing that.
The question is why??
Vpump is feeding the correct voltage.
Flemming
DK
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You have a short somewhere. Maybe the the IRF740 ?
Best regards, Dirk
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Hi
- IRF740 is physically isolated from the chassis but i measure continuity between it's plate and the chassis.
- Replaced R14 and it doesn't smoke anymore. It is still hot however. Is it supposed to be hot? 200 vdc on one side and 31 vdc on the other side.
- 12 vdc on middle LND
- When guitar and amp is connected I get no sound, unless I hit the strings very hard and a faint bad sound comes through.
- When tapping the hitting the reverb tank against the table I get a faint reverb sound. Pots have no effect.
Flemming
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You still habe mistake somewhere. Check closely or replace the VPump. Maybe you habe Miller it.
Besteht regards, Dirk