Valve/Toob suggestions for Blackface build

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Terexgeek
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Re: Valve/Toob suggestions for Blackface build

Post by Terexgeek »

jeremyb wrote:
Terexgeek wrote:
jeremyb wrote:If only line 6 could squeeze an hd500 into a glass bottle :(
It's Helix now, Hee-lix.

Like a lonely hearts ad promoting cunnilingus skills.
So are you saying the heelix is for carrnnts?
Well I want one so yes.
Tin arse!!

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Re: Valve/Toob suggestions for Blackface build

Post by Cdog »

RectifiedAmps wrote: Yeah, the JJ 5881 seems to be a bit closer to a 6L6GC than the TungSol version. I doubt 30VDC or so over the maximum will matter much, and the TungSol datasheet shows traces as high as 600V, too. Maybe just give extra respect to the other parameters a bit more and don't flog them - ie. don't bias them unusually hot or run flat-out into an attenuator. The idle voltage should also drop a fair amount when you drive a signal and increase current draw, especially if you're using a saggy rectifier source. Also, if you're building it from scratch I'd suggest omitting the standby switch since they only cause more problems than they solve - if it's a pre-drilled kit chassis, you could use the hole for a panel-mount B+ fuse instead.
Thanks for the tips! :)

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Re: Valve/Toob suggestions for Blackface build

Post by calling card »

Cdog wrote:Gah... It's a rabbit hole. Now I'm thinking of changing the rectifier to a 5U4GB... just read it drops ~50V compared to the GZ34... that would be useful, I really don't need the full 45W, and it will be fine with my PT. :thumbup:

Reading through some mods, I have some NOS ECC82s which might come in handy.
Tung Sols... Hmmmm
Fascinating things are the rectifier bottles and what the numbers mean. I just set out to find out how comparable the GZ34 with the 5AR4 as written on the inner cabinet label on my Bassman is.

Might be what you've seen already, gleaned off net etc..

"Five Volt Fullwave Rectifier Tubes:
Tube# - Base - Fvolt - Famp - Vdrop - MaxPmA - MaxPv - notes
5AR4/GZ34-5DA - 5.0 - 1.9 - 17 - 250 - 450 - low Vdrop 5U4/5Y3
5AS4-A - 5T - 5.0 - 3.0 - 50 - 275 - 450 - improved 5U4
5AT4 - 5L - 5.0 - 5.5 - 30 - 800 - 550 - higher power 5U4
5AU4 - 5T - 5.0 - 3.75 - 50 - 325 - 400 - high power 5U4
5AW4 - 5T - 5.0 - 3.7 - 46 - 250 - 450 - long life 5U4
5AX4-GT - 5T - 5.0 - 2.5 - 65 - 175 - 350 - high power 5Y3
5AZ3 - 12BR - 5.0 - 3.0 - 44 - 275 - 600 - compactron 5U4
5AZ4 - 5T* - 5.0 - 2.0 - 60 - 125 - 350 - loctal 5Y3
5BC3 - 9QJ - 5.0 - 3.0 - 53 - 300 - 500 - compactron
5CG4 - 5L - 5.0 - 2.0 - ? - 125 - 400
5DJ4 - 8KS - 5.0 - 3.0 - 44 - 300 - 600 - redesigned 5U4 (higher volts)
5R4-G/GY- 5T - 5.0 - 2.0 - 67 - 250 - 750 - high voltage 5U4
5R4-GYA - 5T - 5.0 - 2.0 - 67 - 250 - 750 - high voltage 5U4 (ruggedized)
5R4-GYB - 5T - 5.0 - 2.0 - 63 - 250 - 900 - high voltage 5U4 (ruggedized)
5T4 - 5T - 5.0 - 2.0 - 45 - 225 - 450 - metal 5U4
5U4-G - 5T - 5.0 - 3.0 - 44 - 225 - 450 - octal 5Z3
5U4-GA - 5T - 5.0 - 3.0 - 44 - 250 - 450
5U4-GB - 5T - 5.0 - 3.0 - 50 - 275 - 450
5V3 - 5T - 5.0 - 3.8 - 47 - 350 - 425 - higher power 5U4
5V3-A - 5T - 5.0 - 3.0 - 42 - 415 - 550 - 5V3 reduced filament current
5V4-G/GA- 5L - 5.0 - 2.0 - 25 - 175 - 375 - octal 83-V
5W4-G/GT- 5T - 5.0 - 1.5 - 45 - 100 - 350 - low power 5Y3
5X4-G - 5Q - 5.0 - 3.0 - 58 - 225 - 450 - 5U4 diff pinout
5X4-GA - 5Q - 5.0 - 3.0 - 47 - 250 - 450
5Y3-G/GT- 5T - 5.0 - 2.0 - 60 - 125 - 350 - octal 80
5Y4-G/GT- 5Q - 5.0 - 2.0 - 60 - 125 - 350 - 5Y3 diff pinout
5Z3 - 5T - 5.0 - 3.0 - 58 - 225 - 450 - 4pin 5U4
5Z4 - 5L - 5.0 - 2.0 - 20 - 125 - 350 - low drop 5Y3
80 - 4C - 5.0 - 2.0 - 60 - 125 - 350 - 4pin 5Y3
83 - 4C - 5.0 - 3.0 - 15 - 225 - 450 - 4pin mercury vapour
83-V - 4C - 5.0 - 2.0 - 25 - 175 - 375 - 4pin 5V4
5931 - 5T - 5.0 - 3.0 - 47 - 300 - 600 - industrial 5U4
6004 - 2AJ - 5.0 - 2.0 - 60 - 120 - 375 - rabbit ear 5U4
6087 - 5L - 5.0 - 2.0 - 50 - 125 - 350
6106 - 5L - 5.0 - 2.0 - 60 - 125 - 350
6853 - 8HE - 5.0 - 1.7 - 60 - 125 - 350

274B ~ 5U4G ~ CV575 ~ 5RGY ~ 5(micro)3C(=russisk 5U4) ~ 5Z3P(=china 5U4)
2024; I have explored the extent of the perimeter dome, there is no escape. I am become Morpheus

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Re: Valve/Toob suggestions for Blackface build

Post by calling card »

Under MaxPv heading, is that voltage what the rectifier valve outputs to? or other factors relate to that factor as well. Looking at the industrial grade 5U4 (5931) where it targets 600v. I see 3 amp draw too, would be bad where 2 amp is stock I guess.
Quite the rabbit hole innit.
2024; I have explored the extent of the perimeter dome, there is no escape. I am become Morpheus

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Re: Valve/Toob suggestions for Blackface build

Post by RectifiedAmps »

calling card wrote:Under MaxPv heading, is that voltage what the rectifier valve outputs to? or other factors relate to that factor as well.
I believe thats the maximum plate voltage, so the design limit on what AC your power transformer can input into the rectifier. The output DC voltage will depend on the input RMS AC, the amount of current drawn and which rectifier youre using- you’d have to consult the operation characteristics curves on their individual datasheets. But generally speaking you should get around 70-80% of the RMS AC out of it as DC at idle conditions.

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Re: Valve/Toob suggestions for Blackface build

Post by Cdog »

And ordered! Thanks everyone for the input, greatly appreciated.
TungSol 12AX7s & 5881s, with a JJ 5U4GB. I have NOS bottles kicking around for the remaining preamp spots... woo! :)

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Re: Valve/Toob suggestions for Blackface build

Post by Bg »

did you say you needed a cab?
So, is that low alcohol or no alcohol at all? mmmm, no alcohol, do you want to try it? Noooooooooo.

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Re: Valve/Toob suggestions for Blackface build

Post by Cdog »

Bg wrote:did you say you needed a cab?
Nah bro... cabbed up right before your mad skillz became available. This project is already over a year old :cry:
One day I'd love to get some of that BG tweedness :thumbup:

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Re: Valve/Toob suggestions for Blackface build

Post by Bg »

Cdog wrote:
Bg wrote:did you say you needed a cab?
Nah bro... cabbed up right before your mad skillz became available. This project is already over a year old :cry:
One day I'd love to get some of that BG tweedness :thumbup:
Just don't put any buggered v30's in there or I'll piss in your cornflakes :mental:
So, is that low alcohol or no alcohol at all? mmmm, no alcohol, do you want to try it? Noooooooooo.

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Re: Valve/Toob suggestions for Blackface build

Post by Bg »

jeremyb wrote:
Terexgeek wrote:
jeremyb wrote:If only line 6 could squeeze an hd500 into a glass bottle :(
It's Helix now, Hee-lix.

Like a lonely hearts ad promoting cunnilingus skills.
So are you saying the heelix is for carrnnts?
and banned. both of yers
So, is that low alcohol or no alcohol at all? mmmm, no alcohol, do you want to try it? Noooooooooo.

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Re: Valve/Toob suggestions for Blackface build

Post by tubeswell »

Bog standard Sovtek 6L6WXT (which are a kind of 5881/6P3Se equivalent but not 'coin bass') will work fine and you can still get them relatively cheap. Bias them as if they are 23W max diss. I've put these in a few Super Reverbs as replacement tubes and none of them have boomeranged back to me (touch wood)

As for rectifiers, in a vintage 66 SR I re-tubed a few months ago, I got a B+ of 460 with a JJ GZ34, which is about bang on
He who dies with the most toobs... wins

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Re: Valve/Toob suggestions for Blackface build

Post by Cdog »

Great to hear, thanks tubeswell :)

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Re: Valve/Toob suggestions for Blackface build

Post by Cdog »

Quick question for the experts... What would you fuse the mains input on a Super Reverb at 230v? 1A Sloblow? Mojotone sent me 2A fuse, but I'm assuming that's for US mains... :think:

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Re: Valve/Toob suggestions for Blackface build

Post by RectifiedAmps »

I’d try a 1A slow and see if it holds up- it should do. Always safer to go too low than too high.

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