DIY DC blocker?

[Reid Malenfant]

Yes, they'll be ok to run your amplifier

[HighFidelityGuy]

Cool, how about my pair of 250W class A/B subs? Would one of these filters run one sub ok? Cheers.

[Reid Malenfant]

You'd need capacitors with a higher ripple current rating to be safe. Your valve amp may well consume up to about 1Amp or maybe a tad more, a 2200mA rating is therefore OK. A 250W sub may well use 500W or more which is over 2Amps at 230V...

Got the MUR3040PT sat in front of me

[HighFidelityGuy]

Ok, so I need to match the ripple rating of the caps to the current consumption of the connected device? That makes sense.

With your diode and my caps I can make something to compare against the filter David is sending me, so that will be interesting. Then based on what I find I'll look at making something to protect my subs and other gear.

[Reid Malenfant]

Looky, if you bought these you could damn near if not power your whole setup. Connect two in parallel so you get 13,600uf & you'll have a 14A ripple current rating

First ones i came accross

[HighFidelityGuy]

Thanks Mark, I'll have a look around. I've found some with over 30A ripple rating but they're rather expensive and rather overkill.

[Reid Malenfant]

Talking of capacitors i realised i needed some for a project There are 2 x 1KVA toroidal transformers & 28 x 0.8C/W heatsinks calling their name

I sense a pair of balanced output class A monoblocks in the offing Looks like i'm going to stick with solid state after all..

[Reid Malenfant]

Well bugger me, the seller just sent me a message letting me know he'll post tomorrow. Better yet he has another 14 of these caps & he'll let me have them for £10 postage included

No brainer

[jantheman]

I currently have some issues where my valve amp tranny runs hot and my sub trannies intermittently buzz to varying degrees through the day. So I'm thinking I may have a DC offset issue on my mains.

Heres a quote from the Kemp electronics website which may help you.

'To determine, if you actually suffer from DC on your mains, act as follows:Listen carefully close to your equipment, if you have any hum at all. If the answer is yes, then stay there for a while, and listen carefully. Does the hum alter in time, you can be sure, that DC on the line is the cause of this hum. Do you hear a very constant hum, always present and always the same loudness, the transformer itself may well be the cause'.

And a link to the page.
http://www.kempelektroniks.com/getdo...aspx#pdcxcplus

Not sure if you want to buy one..they are over 300 squids.......

[HighFidelityGuy]

Thanks Ray, that's exactly what I hear, a transformer hum that changes in volume. Most of the time it's very quiet and constant, then it suddenly swells to a level where you can hear it across the room and starts going up and down every few seconds. Then after a few minutes it dies down again. I haven't been able to attribute it to anything plugged in in my house, so it must be coming from an external source. I live fairly close to some steel works and other heavy industry, so I guess it must be them firing up some big machines.

Until reading about mains DC offset I'd just assumed it was the mains voltage changing but after monitoring this for a couple of weeks I began to doubt that theory. I was starting to think I'd either have to live with it or buy an expensive mains regenerator but hopefully one of the solutions mentioned here will help for a lot less money.

Cheers.