Heater Considerations for new build

[Opry Audio]

I just ordered a right angle Princeton reverb chassis for my next build, and I’m not overly happy with it. The preamp tube mounting holes are pretty close to the edge of the chassis and just considering my options for heater wiring. It’s too close to run them along the edge, not enough room, if I flew them, they would run very close to the switch, fuse and speaker jack. The only problem I could see is running them close to the speaker jack, yeah?

I’m wondering about series heaters like in SLO builds with bare wire running along each side. I think it LOOKS great but what are the reasons for not doing it? Is it something I could get away with in a *not so* high gain amp? I have seen a few threads about this kind of heater wiring, even with Marshall series wiring, some of those amps are super quiet. Should I give it a shot? It’s a lot of extra work if it’s no good so I would definitely like to know if it’s worth attempting or if I should just fly them and not worry about it.

My general plan is to build the Hoffman AC30 top boost preamp with a parallel input stage like matchless and CF tone stack. Parallel reverb driver and single triode recovery and a cathodyne phase inverter and push pull cathode bias 6V6’s and an 8k OT for the tweed deluxe flavor, maybe a high cut control. Working on a schematic now and should have enough room to do all of this in this chassis.

[shooter]

my last 3-4 SE amps have all used || heater wires no problem.  I like to run them "on the chassis" directly on either side of sockets.  I use stranded/soldered so the "stiffness" keeps them low n tight 

[Opry Audio]

my last 3-4 SE amps have all used || heater wires no problem.  I like to run them "on the chassis" directly on either side of sockets.  I use stranded/soldered so the "stiffness" keeps them low n tight 

Thanks! Do you think there would be a significant difference between using covered cloth or Teflon wire, as opposed to bare wire a la SLO?

[Willabe]

Can you show us a pic or give a link that has a pic of it?

[Opry Audio]

https://orig02.deviantart.net/af8e/f/2014/208/8/4/slo_clone_2_by_haftelm-d7sk6zc.jpg

There’s a diyaudio thread with the same question in question but most answers I can find are “this goes against everything about heaters” and “Soldano is the exception” but kinda interested in why

[shooter]

I use this mainly for how to lead dress, but has the heaters.  I started once Sluckey did his like that 

[Opry Audio]

 

I use this mainly for how to lead dress, but has the heaters.  I started once Sluckey did his like that 

What a great looking build. That’s exactly how I’m thinking of doing it

[shooter]

NOT my build
but I have that n one of Steve's I tape up when I build, just so I know what it should look like 

[sluckey]

I use this mainly for how to lead dress, but has the heaters.  I started once Sluckey did his like that 

Ugh, I have never wired heaters like that.

[Willabe]

https://orig02.deviantart.net/af8e/f/2014/208/8/4/slo_clone_2_by_haftelm-d7sk6zc.jpg

There’s a diyaudio thread with the same question in question but most answers I can find are “this goes against everything about heaters” and “Soldano is the exception” but kinda interested in why

No, I mean a pic of the Princeton Reverb chassis you bought.

[shooter]

Ugh

details 
You went one step future and did loops just to bother RF folk 

[sluckey]

You went one step future and did loops just to bother RF folk

Ah, yes. I did do that! 

[Willabe]

I just ordered a right angle Princeton reverb chassis for my next build, and I’m not overly happy with it. The preamp tube mounting holes are pretty close to the edge of the chassis and just considering my options for heater wiring. It’s too close to run them along the edge, not enough room, if I flew them, they would run very close to the switch, fuse and speaker jack. The only problem I could see is running them close to the speaker jack, yeah?

What is a 'right angle' chassis?

If you show us a picture of the chassis you ordered we could probably tell you if it will be a problem with the heater wires or not.

[Opry Audio]

Here’s a pic of the chassis, tube sockets installed for reference!

[Willabe]

Looks like a standard Princeton chassis.

Are you calling it a 'right angle' chassis because the front panel is angled back?
Oh, you mean your's is NOT angled back?

Here's a gut shot of a Fender Princeton Reverb, heaters are flown above the tube sockets. All the Fender black face and silver face were done like that. They all have their heater wires going by the fuse/power switch/standby switch/speaker jacks.

[Willabe]

Here’s a pic of the chassis, tube sockets installed for reference!

They did move the small 9 pin tube sockets closer to the side wall.

Fenders have all the tube centered in a line.

Tell him he messed it up and send it back and get 1 that's tube socket holes are punched in a centered line.

Mojo sells them. They have front/back plates too. 

http://www.mojotone.com/amp-parts/ChassisCapPans_1/Blackface-Princeton-Reverb-AA1164-Style-Chassis

[Willabe]

What are you going to do for a cab?

[Opry Audio]

What are you going to do for a cab?

I’m not totally sure yet, I found this chassis for cheap on the bay and I guess you get what you pay for 

As far as a cab, I’m gonna try my hand at getting a decent CAD file set up and have it cut on a CNC mill. I have a friend who’s very wood savvy and might call in a favor!

Other than this the chassis is totally fine for what I need it for, I guess the speaker jack mounting hole sits a little low but it’s not terrible. I might just make due with it for now, it’s for a prototype anyway. It’s my 4th build and I’m just taking my time with it, I will upload a schematic for you all to roast soon— it takes me a little while.. still getting used to ExpressSCH I really like it better than diylc for schemes

[Greg]

Hi... Your speaker will never pick-up hum from the heater running near the speaker jack that's for sure. Unless it «makes» a connection. Personally, I would not run bare heater wires inside an amp but I see it has been done. But you can wire them how you like accordingly to the chassis you have. As long as it doesn't run parallel with a high impedance wire, you are ok.

[Opry Audio]

I just got some 20awg Teflon wire that will fit after all.. I might save the bare wire idea for another build where the tube sockets are more strategically placed for it. For now I’m not gonna mess with something that ain’t broke

[kagliostro]

+01 for Willabe submission



only I'll twist better the wires and you can keep them even more lifted by the sockets

--

other option I'm trying (building in a small cabinet a Gibson Skylark ga-5t) is this



the aluminium square pipe you see on the right bottom is planned to be used as shield for the heaters wires (with holes on tube correspondance), if aluminiun will not give good results, I'll try an iron pipe (I've seen something like this used by HiFi guys)

Franco

[glass54]

Hi Franco,
Just a couple comments, hopefully useful . Copper is probably the most reliable metal in EMI shielding, used in MRI machines, etc. (Obviously easily soldered)
Aluminium has excellent strength to weight ratio and about 60% conductivity compared to copper but is prone to oxidation.
Nice twists in your Heater Wires, Opry (I like)
Kind regards,
Mirek

[kagliostro]

Some time ago I followed a tred of a guy who was shielding a transformer to avoid noise problems he spread in the amplifier

he tried to shield the transformer with different metals (I don't remember but seems he didn't tried with MUMetal) and the "winner" was alluminium

Unfortunately the thread was closed years ago and I was no more able to share the link

Franco

p.s.: My intention is to twist the wires inside the pipe

[shooter]

Obviously easily soldered

I use copper sheet to "cover" my chassis, re-cycled from and MRI RF room.  It's to thin to torch solder, and so much surface area my 300W 2' iron struggles, even with flux.  I've moved to glued/lapped mechanical, lots cleaner