Dynacord Tremolo MIA

[jamesedmunda]

I'm restoring a Dynacord Tween but can't get the tremalo working. I get 84vdc on v2a
plate but the voltage goes up slowly to270vdc when I pull the tube.
.

[sluckey]

Looks like everything under the chassis has been changed. I'm sure you have all correct values and the wiring is correct???

[Latole]

Shematic 

http://www.peel.dk/Dynacord/


https://elektrotanya.com/dynacord_tween_valve_amplifier_2x6v6_sch.pdf/download.html

[thetragichero]

so would you say... the tremolo es malo?

[Latole]

Often ( if not most of the time ) in original ( no mods ) and working amp, when tremolo do not work, it is a capacitor issue. Replace all tremolo capacitors
.01 mfd, .022 mfd, .033 mfd as see on last schematic.

[sluckey]

Often ( if not most of the time ) in original ( no mods ) and working amp, when tremolo do not work, it is a capacitor issue. Replace all tremolo capacitors
.01 mfd, .022 mfd, .033 mfd as see on last schematic.

The tremolo caps are .022, .01, and .022 according to the schematic in the original post and also the last schematic you posted.

[Latole]

Often ( if not most of the time ) in original ( no mods ) and working amp, when tremolo do not work, it is a capacitor issue. Replace all tremolo capacitors
.01 mfd, .022 mfd, .033 mfd as see on last schematic.

The tremolo caps are .022, .01, and .022 according to the schematic in the original post and also the last schematic you posted.

You are right, .033 is only the coupling cap

[sluckey]

You are right, .033 is only the coupling cap

If you look at the pdf schematic in the original post you can clearly see that C11 is 0.33µF, not .033µF.

[Latole]

You are right, .033 is only the coupling cap

If you look at the pdf schematic in the original post you can clearly see that C11 is 0.33µF, not .033µF.

Not enough coffee this morning

[sluckey]

Probably too much here.   

[jamesedmunda]

Ok I've gone over all the values and everything seems good. All the caps are new except for one mica on the tone. Output trans is from a Carls Custom Deluxe amp. Here's the voltages they seem off on v2a only 84vdc on the plate, pull the tube and its 180vdc.

[sluckey]

84v is probably about right with that 510K plate resistor. But if the tremolo tube was working, the plate voltage would be changing at the speed of the trem oscillations. This would appear as an erratic reading on a DMM. Steady voltage indicates the oscillator is not working.

You need a strong 12AX7 for a tremolo oscillator to work so try several different tubes first. Typical suspects would be C9, c12, and/or C13. Also resistors and speed pot. And since you have replaced every component in that point to point circuit, you have to also suspect a wiring error.

[jamesedmunda]

Thanks for the interest. This is a power tube bias tremalo correct. I have a 220 ohm bias resister cause it was running hot.
 Funny how the signal dies at the .33 cap C 11. I've tried other tubes still no wiggle.

[PRR]

> dies at the .33 cap C 11.

Did you replace it?

[sluckey]

Funny how the signal dies at the .33 cap C 11.

What signal are you talking about? If the plate voltage is steady 84v, the tube is not producing ***ANY*** signal.

[jamesedmunda]

Here is a couple snaps, maybe I'm missing something.
Dought you tell by looking, its a mess.

[Latole]

Here is a couple snaps, maybe I'm missing something.
Dought you tell by looking, its a mess.

Not only a mess, it is a rat nest 

[sluckey]

The 510K plate resistor for V2 pin 1 is wired wrong. Fix it and maybe the trem will work.

[jamesedmunda]

Thank You Mr. Sluckey.
 Tremalo sounds great.
If your ever in Chicago I'll buy you a Beef.