DHT Heater using VCCS - PCB or Kit (Possible Group buy)

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Ray P
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#811 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Ray P »

Thanks Andrew.

There has been some small level of interest in the DC project over on the Transcendent site. What's the availability situation with the boards as it would be good to tell people in case their interest develops.

Cheers

Ray
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Andrew
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#812 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Andrew »

Hi Ray,

I've got plenty of the ones that mount onto a separate heatsink and if there's enough interest I can get more of the ones with the heatsink on the PCB made up, shouldn't be a problem, I just need to know numbers.

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#813 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by IslandPink »

Andrew -
Just made up another 4P1L supply , this time on one of the 'smart' finished PCB's . Checking the old Proto ones I saw Rx = 4k7 and Ry = 3k3 . I therefore tried those values rather than the 4.2/3.3 listed in 'Stacks' section. Again, the voltage came out spot-on at 4.2V after a couple of minutes warm-up.
Maybe you could check this yourself some time, and if you get the same, perhaps update the 'Stacks' advice to correspond ?
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#814 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Andrew »

Done.

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#815 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Ray P »

Hi Andrew, I'm tinkering around a possible new project using a #26 valve in a preamp. The info I've been checking out is using Coleman regs in a filament biasing configuration, like this;

https://www.dropbox.com/s/pg34er1szexle ... y.pdf?dl=0

http://www.diyaudio.com/forums/tubes-va ... ost3303081

I have a couple of your 'big' DHT kits so using them seems an obvious thing to consider; can you see any problems with that? I'm thinking that to replicate the configurations above I would set the output to 10V as per the Coleman information.

Cheers

Ray
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davebms
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#816 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by davebms »

this could be good stuf,, im looking at 4p1l as a pre amp. I have 2 small
dht boards will they work ok

dave
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#817 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Andrew »

Small or big is fine for the smaller preamp valves like 26 and 4P1L.

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#818 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Ray P »

davebms wrote:this could be good stuf,, im looking at 4p1l as a pre amp. I have 2 small
dht boards will they work ok

dave
Dave, what circuit are you looking to use?

I've also bought some 4P1L valves and plan to use them (and the #26s) with the Bartola gyrator. In case it's of interest here are links to some of the Bartola 4P1L projects;

http://www.bartola.co.uk/valves/dht-pre ... amplifier/

and with the gyrator;

http://www.bartola.co.uk/valves/2015/02 ... 1-upgrade/

Andrew, just out of interest, do you have any more of the boards available? If so I would like some for the spares box.

Ray
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#819 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by simon »

Ale's PCBs work well Ray, I've just changed the anode chokes I was using to load 26s for gyrators and there is an improvement I think. More detail, better separation of instruments, more dynamics, and deeper bass (no surprise as the 26 needs a lot of H for deep bass). It's still early days but I like them so far.

They're compact too and Ale reckons the excellent PSRR makes the PS easier. I think I'll get another pair for the 10Ys.
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#820 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Ray P »

simon wrote:Ale's PCBs work well Ray, I've just changed the anode chokes I was using to load 26s for gyrators and there is an improvement I think. More detail, better separation of instruments, more dynamics, and deeper bass (no surprise as the 26 needs a lot of H for deep bass). It's still early days but I like them so far.

They're compact too and Ale reckons the excellent PSRR makes the PS easier. I think I'll get another pair for the 10Ys.
Thanks Simon. What filament supplies are you using?

Ray
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#821 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by simon »

v2 Coleman regs in self bias. I'd like to try filament bias sometime but need to change my raw DC to do so.
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#822 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by davebms »

]

Dave, what circuit are you looking to use?

I've also bought some 4P1L valves and plan to use them (and the #26s) with the Bartola gyrator. In case it's of interest here are links to some of the Bartola 4P1L projects;

http://www.bartola.co.uk/valves/dht-pre ... amplifier/

and with the gyrator;

http://www.bartola.co.uk/valves/2015/02 ... 1-upgrade/

Andrew, just out of interest, do you have any more of the boards available? If so I would like some for the spares box.

Ray[/quote]
thanks for the links I have seen these, I want to try to get Andrews boards up to 11volt out, for filament biasing and keep the rest as simple as possible !!!
gyrators I find things like them I blow up!!!
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#823 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Andrew »

I have a few remaining PCB.

Cheers,

Andrew
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#824 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by Max N »

Hi Andrew
Do you have any of the DHT PCBs or kits left?
Ideally I'd like 4 off for 45s, 4 off for 300Bs, and 4 off for 211s

While I'm at it, do you have any of the IDHT heater boards or kits left?

Cheers

Max
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#825 Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Post by simon »

Sounds like quite an amp Max! Please tell us it's a balanced 45-300B-211 amp :-)
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