7W, 6336A SE Amplifier

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Cressy Snr
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7W, 6336A SE Amplifier

Post by Cressy Snr » Sat Jul 20, 2019 2:55 pm

Since my small push-pull amp has turned into a single-ended job, I’ve started a new thread. The PP amp is not dead.....yet, but it’d be daft to talk about it in a push pull amp thread. As usual I’ve got diverted.

I really like the sound of SE amps, built with regulator valves. For example, the recently built 13E1 SEOTL is, for me, a milestone project that sets a standard that this 6336A project is not going to reach, but I’d rather have more than one valve amp in my collection, for those times when I feel like swapping things around. And it’ll be something new for Owston 2020.

So....
6336A curves:
Image

260 ish on the anodes and 90mA idle current at 80 ish Vk looks decent to me.

2K5 loadline.
Last edited by Cressy Snr on Sat Jul 20, 2019 2:57 pm, edited 2 times in total.
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Cressy Snr
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Re: 7W, 6336A SE Amplifier

Post by Cressy Snr » Sat Jul 20, 2019 2:56 pm

Some working out (not mine, but why reinvent the wheel)

Image

The blue line gives 26.1W plate dissipation per section, plus the 31.5W of heaters. This means having to shift 83.7W of heat from a bottle the size of a KT88
The green line at 23.5W per section is a little cooler at 78.5W to manage. The valve is designed to manage this heat, but it’s a bit warm to say the least. I’ll probably go for the green line, even though the max distortion is slightly higher at full power.

Driver needs to swing 160V pk-pk, so a simple 6SN7, or 12AU7 cascade will easily manage it on a shallow load line.
Last edited by Cressy Snr on Sat Jul 20, 2019 3:32 pm, edited 1 time in total.
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Cressy Snr
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Re: 7W, 6336A SE Amplifier

Post by Cressy Snr » Sat Jul 20, 2019 3:01 pm

If I choose a 6SN7 cascade to drive the 6336A, I might even be able to adapt the pair of SEOTL driver PCBs, Ray sent me last year. It should work nicely with only a couple of component value changes.
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Ray P
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Re: 7W, 6336A SE Amplifier

Post by Ray P » Sun Jul 21, 2019 1:27 pm

Cressy Snr wrote:
Sat Jul 20, 2019 3:01 pm
If I choose a 6SN7 cascade to drive the 6336A, I might even be able to adapt the pair of SEOTL driver PCBs, Ray sent me last year. It should work nicely with only a couple of component value changes.
Should you need a spare or two Steve I'm sure I've got a few more of the 6SN7 boards somewhere here.

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Re: 7W, 6336A SE Amplifier

Post by Cressy Snr » Sun Jul 21, 2019 3:17 pm

Ray P wrote:
Sun Jul 21, 2019 1:27 pm
Cressy Snr wrote:
Sat Jul 20, 2019 3:01 pm
If I choose a 6SN7 cascade to drive the 6336A, I might even be able to adapt the pair of SEOTL driver PCBs, Ray sent me last year. It should work nicely with only a couple of component value changes.
Should you need a spare or two Steve I'm sure I've got a few more of the 6SN7 boards somewhere here.
Cheers Ray. I may have to take you up on that, as I seem to have mislaid the 6SN7 boards. :(
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Ray P
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Re: 7W, 6336A SE Amplifier

Post by Ray P » Sun Jul 21, 2019 5:58 pm

I'll see if I can find them just in case then.

Ray

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Re: 7W, 6336A SE Amplifier

Post by Ray P » Mon Jul 22, 2019 10:20 pm

I've found the boards Steve, I have half a dozen of them should you need any.

Ray

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Re: 7W, 6336A SE Amplifier

Post by Cressy Snr » Tue Jul 23, 2019 11:02 am

Ray P wrote:
Mon Jul 22, 2019 10:20 pm
I've found the boards Steve, I have half a dozen of them should you need any.

Ray
It’s OK Ray, I’ve found the blighters. :)
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