# Tube Heater Wiring



## Lincoln (Jun 2, 2008)

I think we're all pretty used to seeing the "twisted pairs" type of wiring for the heater circuit on tube amps. But I've been wondering........every Garnet amp I've ever looked in doesn't use twisted pairs. They all have straight wires run along the floor of the chassis from one tube to the other with no twisting at all except from the PT to the first tube. How did Gar get away with that? His amps don't hum. They seemed to have run the heater wires first, kept them right tight on the floor of the chassis and then run the other wiring over top of them. Looks a lot easier than what I've been doing. Is it acceptable or am I missing something? 

An example, a Garnet Pro 200. The heater wires are white.


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## WCGill (Mar 27, 2009)

It's definitely not best practice, although putting them tight to the chassis helps. It's possible with Gar's layout there are no signal wires in close proximity to pick up the noise. Gar made some amazing stuff, some of it pretty minimalist.


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## Church-Audio (Sep 27, 2014)

Lincoln said:


> I think we're all pretty used to seeing the "twisted pairs" type of wiring for the heater circuit on tube amps. But I've been wondering........every Garnet amp I've ever looked in doesn't use twisted pairs. They all have straight wires run along the floor of the chassis from one tube to the other with no twisting at all except from the PT to the first tube. How did Gar get away with that? His amps don't hum. They seemed to have run the heater wires first, kept them right tight on the floor of the chassis and then run the other wiring over top of them. Looks a lot easier than what I've been doing. Is it acceptable or am I missing something?
> 
> An example, a Garnet Pro 200. The heater wires are white.
> View attachment 10194


He might have been using a center tap teansformer for the heater that helps... Or a virtu tap with two 100 ohm resistors as fender did / does on some of there amps. I have fixed a few garnets can't recall off the top of my head. Twisted pair is always the way to go. But honestly if you can keep the heater wires away from other things that might get induction you should be ok. Ampeg was like this too on some of the amps from the 1960s. Also any circuit board amp is not going to have twisted pairs. Again board layout is importaint there. I always start when I build an amp with some nice 18ga cloth wire I get from mojotone twist it up really tight then wire the amp and cut the pair as I need too. Keeps it looking nice. Gibson had huge problems with heater noise in some of the amps they made
in the 1960.. The cleaner a layout is chances are the better the amp will perform and last and be easy to service.


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## Lincoln (Jun 2, 2008)

Amprepair said:


> He might have been using a center tap teansformer for the heater that helps... Or a virtu tap with two 100 ohm resistors as fender did / does on some of there amps. I have fixed a few garnets can't recall off the top of my head. Twisted pair is always the way to go. But honestly if you can keep the heater wires away from other things that might get induction you should be ok. Ampeg was like this too on some of the amps from the 1960s. Also any circuit board amp is not going to have twisted pairs. Again board layout is importaint there. I always start when I build an amp with some nice 18ga cloth wire I get from mojotone twist it up really tight then wire the amp and cut the pair as I need too. Keeps it looking nice. Gibson had huge problems with heater noise in some of the amps they made
> in the 1960.. The cleaner a layout is chances are the better the amp will perform and last and be easy to service.


It does have center taps on both the HV and filament windings. It also used shielded wire from the input to the pre-amp tube AND from the pre-amp tube to the phase inverter tube.

It's been a very trouble-free amp. I've owned it since the mid-70's and aside from power amp tubes it's never had a thing done to it. Pots are worn out now but it's still going strong & quiet (even with the original filter caps). It's even still got the original 2 conductor cord and a death cap!


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## nonreverb (Sep 19, 2006)

Garnet made some great stuff. I have a couple of customers who collect them. One has just about everything Gar ever made.


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## jb welder (Sep 14, 2010)

Anybody got one of those funky centre-tapped chokes Garnet used for phase splitter in some models? Let me know as they seem to be extinct/unobtainium.


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