WD Phono heaters.

[bikerhifinut]

Just a quick question Phil.
Whats the voltage off your secondary for the heaters? if its a 6.3V secondary you aren't going to get a standard or even low dropout voltage regulator to work I would think.
If theres enough current available, you could consider a voltage doubler if thats the case. it's a trick that John Broskie uses in his PSU PCB kits.

[Phil Y]

Yes, I realized that a few days ago but the transformer has a 6-0-6, 1 amp winding that is not being used. It is just that it would be a fair bit of work to do the job hence my question about whether 160mV ripple is an issue.

Phil.

[colin.hepburn]

bit of a guess here but this maybe the version is what Phil is talking about

[bikerhifinut]

Originally Posted by Phil Y

Yes, I realized that a few days ago but the transformer has a 6-0-6, 1 amp winding that is not being used. It is just that it would be a fair bit of work to do the job hence my question about whether 160mV ripple is an issue.

Phil.

you could easily run a 6.3V heater off that, but you'd still be restricted to 1 amp. 3 x Ecc83 = 900mA of heater current at 6.3v. close.

for what its worth I have had success with the 2velleman 1 amp PSU kit from maplins. easy to build on a neat pcb and you can use other regs instead of a LM317, but you are still restricted to 1A unless you uprate the rectifier diodes.

A.

[bikerhifinut]

If you have the bits it is of course cheaper and just as quick to build one up on a piece of veroboard. The "velleman" kit for me is handy because the PCB on the current version has been slimmed down and its a very compact and neat looking thing. with screw terminals for in and out which makes for a very quick installation. I can solder it in when I am happy with everything.

Andy.

[Phil Y]

Originally Posted by colin.hepburn

bit of a guess here but this maybe the version is what Phil is talking about

That is basically it but it has had a few changes since then.
Thanks for the suggestion Andy, I will look into it.

[bikerhifinut]

no worries Phil.
It may be me missing a trick here, but if that's the PSU you are using then it is showing 6.3VAC for the ECC83 heaters. But you mentioned a 12V (6-0-6) secondary so I assume you are using a different transformer. You'll need a voltage doubler if using a 6.3V secondary to regulate back down to 6.3V. Which seems wasteful of current and it is. But it's the only choice to get the minimum 3V voltage difference to get a regulator to regulate well, (assuming a standard LM317 or similar type). I have to admit I use LD1086 types for up to 1A cos I have a lot of em in the scrapbox. As JC mentioned earlier they are low dropout types and will work better in marginal voltage situations.
One thing you might consider is running the valves at 12.6V heaters which will halve the current demand and might have a beneficial effect on heater induced hum and noise.
Now I got to wondering how much space you have inside your PSU and if you could squeeze a small 15V transformer in? You'd need 450mA for 3 ECC83 types and rectify and regulate to 12.6V.
Apologies if I have hold of the wrong end of the stick.

Andy.

[Dave the bass]

Bit an aside question but.... on WD's Phono 3, are the heaters elevated on a DC level per chance? If yes, any idea how high? Ta.

DTB

[Richard]

Hi Dave, yes +40V

[Dave the bass]

Originally Posted by Richard

Hi Dave, yes +40V

Hello Richard, long time! Thanks for the answer, cheers, thought someone here might know. I'm experimenting!