Silvertone 1484 Tremolo Ticking

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Silvertone 1484 Tremolo Ticking

Postby menschmaschine on Sat Oct 01, 2016 7:58 pm

Hey Guys,

Anyone ever hear that in a Silvertone 1484 before? I have this ticking in the tremolo I just can't get rid of. I was able to reduce it significantly, but it's still there. It ticks in time with the speed and it becomes audible when the strength knob is turned past 11:00 (after that it's more or less a constant volume in the ticking). I reduced it by re-routing the wire that goes from the LDR to the trem tube, but no more amount of wire moving makes it go away completely. The ticking isn't loud and it's not really noticeable while playing notes, but I'm trying to sell this and have a buyer who wants it primarily for the tremolo! He told me if I can fix the tremolo, he'll buy it. He heard it before I moved the wire, but I want to make it completely go away before I tell him I fixed it.

Quick background: most of the entire circuit is new (all caps, resistors, pots, diodes, etc.). The only original circuit parts are the transformers, a few switches, and the optocoupler (could it really be that?... the trem sounds fine otherwise). I've tried a replacement trem tube. I tried putting a 220K resistor in series with the lead (a supposed fix I read online). My old portable black and white TV-turned oscilliscope just makes the trem go off completely...shows no pattern. The only thing that has made a difference is moving the wire as previously stated. Anyone know of a way to make this go away completely?
menschmaschine
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Re: Silvertone 1484 Tremolo Ticking

Postby stratele52 on Sun Oct 02, 2016 9:20 am

A mod for LDR in Fender amp is to put a 0.02 mfd cap on 100K resistor at neon bulb. But Silverstone have not same circuit :(

Did you try new tubes in vibrato circuit or tube with less gain ?
http://www.geofex.com/ampdbug/vibrato.htm
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Re: Silvertone 1484 Tremolo Ticking

Postby menschmaschine on Sun Oct 02, 2016 1:35 pm

stratele52 wrote:A mod for LDR in Fender amp is to put a 0.02 mfd cap on 100K resistor at neon bulb. But Silverstone have not same circuit :(

Did you try new tubes in vibrato circuit or tube with less gain ?
http://www.geofex.com/ampdbug/vibrato.htm


I tried various known good tubes for the trem tube (V6). It didn't make a difference. This seems to be a problem on a few different Fender amps as well and there are various theories out there for it. I think some of the fixes people have had success with are happenstance... probably just moving wires around in the course of the work was what really fixed it in some cases.

I've done some reading up on this problem (in Fender amps) and one of the theories is a sudden voltage drop in the neon bulb. Pending other ideas from this forum, I might just order the Fender replacement LDR and see if that works. It will probably cost me $12-$15 with shipping, but it's the only thing left to rule out. I haven't seen anyone say they had this problem and bought the LDR and that fixed it, but I haven't seen anyone say they tried that and it didn't fix it either.

If that doesn't work, I'm thinking I'm back to putting a .022 cap somewhere, just got to figure out where.
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Re: Silvertone 1484 Tremolo Ticking

Postby stratele52 on Sun Oct 02, 2016 7:29 pm

I'll put a resistor in series with neon bulb and with a 0.02 caps in parallel to the resistor.
Yes a wiring dress may help sometimes.
A Fender LDR may need a different voltage drop resistor,but I'm not sure

Good luck and report
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Re: Silvertone 1484 Tremolo Ticking

Postby menschmaschine on Sun Oct 02, 2016 9:00 pm

One thing I'm curious about (and this is touching on the other recent 1484 thread)... There are two versions of a schematic out there. Aside from the incorrect 6/8 pin switch issue on V6, one version has R56,which runs across pin 3 and 8, as a 27K and R57 (pin 1 to pin 3) as a 15M. Another version has R56 as a 68K and no R57 15M at all! On that version, the next resistor after R56 is R58... there is no R57.

My amp was the latter version. I don't know if this has anything to do with the ticking. Since my amp was a late 1965 or early 1966 version (speaker codes), I hypothesized that this was some kind of correction to something and that the original version (1963?) had the 27K and 15M. I wonder if the ticking would go away if I changed R56 to 27K and added R57 15M.
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Re: Silvertone 1484 Tremolo Ticking

Postby stratele52 on Mon Oct 03, 2016 9:55 am

I'll put the cap in parallel to to R56 , 68K
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Re: Silvertone 1484 Tremolo Ticking

Postby menschmaschine on Mon Oct 03, 2016 12:14 pm

OK. I'll give that a shot and report back.
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Re: Silvertone 1484 Tremolo Ticking

Postby menschmaschine on Mon Oct 03, 2016 11:46 pm

Tried the .022 cap parallel to R56... no good. It made it chirp instead of tick. So, I tried the last thing before I would buy a new LDR... I tried switching it to the other schematic. I got rid of my R56 68K, replaced it with a 27K, and added an R57- a 15M from pins 1 to 3 of V6. DONE! No more ticking (or chirping). Sounds great now. I don't know how these two different schematics came about and mine was clearly originally made with a 68K R56 and no 15M R57. Well whatever it is, it worked. Thanks for your input, stratele52.
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Re: Silvertone 1484 Tremolo Ticking

Postby stratele52 on Tue Oct 04, 2016 8:52 am

Good news !

I never found another schematic for a 1484 ( only the faulty tremolo one ) but a 1485 is what you are talking about with quiet tremolo circuit.
Here;
http://el34world.com/charts/Schematics/ ... ne1485.pdf


Enjoy your amp and have a happy buyer
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Re: Silvertone 1484 Tremolo Ticking

Postby stratele52 on Tue Oct 04, 2016 9:17 am

I build my own Fender LDR with parts found at my electronic store for less the $2
I use some over years on amps, work and look ( with black heat shrink ) like a original Fender part.


Image
Image
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