Dumbleator finish, voltage

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sergio
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Dumbleator finish, voltage

Post by sergio »

Hi all, Today I completed my first dumbleator , I have not tried yet....
This is my schematic with voltage:
I will post some photos..
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Structo
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Re: Dumbleator finish, voltage

Post by Structo »

Hi Sergio,
Looking forward to seeing your loop.
I notice a lot of you guys over there use the toroid transformers.
Is there a reason for that?

I was wondering why you chose to use a 51K plate load resistor on the Recovery plate?

I have similar voltages but my plate voltage on the recovery plate is 213v using a 100K plate load resistor.
Did you find you liked the way it sounds better with lower gain there?

Here is what I ended up with.
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Tom

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sergio
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Re: Dumbleator finish, voltage

Post by sergio »

what type of toroid transformer gives me the chance to put it inside the rack
height only 34mm

I read old posts (I forget which) that the voltage on the second triode (recovery plate) should be around 250v for the proper functioning

maybe I'm wrong, but I remember this...please correct me if this is wrong

100K there I think to run with too low voltage.

Tomorrow I will try my D-lator and I'll let you know.

Ciao!
dogears
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Re: Dumbleator finish, voltage

Post by dogears »

230V or so is the standard.

I'd lower the B+ dropper to raise the plate voltage and go to the 100K. The plate resistor is an integral part of the tone and a low plate will have less bass and be brighter. It changes other things too.

Stick with the 100K.....

Btw, 210V also sounds good.
talbany
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Re: Dumbleator finish, voltage

Post by talbany »

Sergio
The voltage drop across the plate resistor sets the rails on the recovery stage...The higher the value the greater the voltage drop.. Greater the drop the darker the tone as well as increased headroom..Think high plate low plate.. Same basic result.. Like Scott say's change that resistor.. Tone changes along with the headroom on the recovery..Good Luck!!

Tony
" The psychics on my bench is the same as Dumble'"
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sergio
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Re: Dumbleator finish, voltage

Post by sergio »

thanks to everyone for the advice

Sergio
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sergio
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Re: Dumbleator finish, voltage

Post by sergio »

I changed plate resistor on recovery stage with 100K , here my new voltage. and some photo
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Structo
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Re: Dumbleator finish, voltage

Post by Structo »

Looks very nice!
:D
How do you like it with your amp?
Tom

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BobW
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Re: Dumbleator finish, voltage

Post by BobW »

That 's a great job Sergio. 8)
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Structo
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Re: Dumbleator finish, voltage

Post by Structo »

Your heater voltage is a bit high, eh?
Tom

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erwin_ve
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Re: Dumbleator finish, voltage

Post by erwin_ve »

Structo wrote:Your heater voltage is a bit high, eh?
yes it is; I did a 2R2 resistor in series to drop the voltage a little. The torrodial is designed to feed 3 to 4 pre amp tubes.
For the dlator only one tube, that's why the heater voltage is a bit high.
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sergio
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Re: Dumbleator finish, voltage

Post by sergio »

I try it today , it's sounds good with the pots setted high , nothing change of tone.

Yes , my heater voltage is a bit high.

Erwin , you suggest me a 2R2 in series on every HT wire? I understand right?

Sergio
Guitarman18
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Re: Dumbleator finish, voltage

Post by Guitarman18 »

Sergio,

Check this out for sorting out your heater voltage.

http://www.tubecad.com/july2000/page2.html


you suggest me a 2R2 in series on every HT wire
BTW, HT stands for high tension (which is the high voltage secondaries), not heaters (6.3).

So, according to my maths, 1R2 resistors in series with each leg of the heater winding.

Cheers,

Paul.
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erwin_ve
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Re: Dumbleator finish, voltage

Post by erwin_ve »

sergio wrote:I try it today , it's sounds good with the pots setted high , nothing change of tone.

Yes , my heater voltage is a bit high.

Erwin , you suggest me a 2R2 in series on every HT wire? I understand right?

Sergio
No I meant 2R2 (3w)in series with the heater wires. This would drop your voltage to 6,3v.
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sergio
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Re: Dumbleator finish, voltage

Post by sergio »

Excuse me , OK , HT = high tension (high voltage secondaries) :lol:

I will try to insert a resistor in every heater wire.

Ser.
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