A Very Compact Hybrid Amp | Page 45 | Headphone Reviews and Discussion - Head-Fi.org

runeight · Apr 5, 2009 at 4:22 AM

OK. Please check to see if the regulator is oriented correctly and if it is then it's probably toasted somehow. Will need to be replaced.

Did anything unusual happen when the amp fired up? It's pretty hard to burn out one of these regs since they are current limited and thermally protected. But it can happen.

tacitapproval · Apr 5, 2009 at 4:33 AM

Well that's foolish, I put it in backwards. If I swap it round should it still function or will I need a new one?

Thanks for walking me through this. I am definitely learning a lot.

runeight · Apr 5, 2009 at 4:45 AM

It does happen. I've done things like this plenty of times.

It will probably work if you turn it around. When you power up again make the outside pin measurements right away and see what you get. If the LV is 24V then I suspect that the tube plate voltages will be about 80V.

runeight · Apr 5, 2009 at 4:46 AM

And if the tube's plates are near 80V then measure OG. It should be half of the LV, whatever that is.

tacitapproval · Apr 5, 2009 at 5:01 AM

Success!! Voltages check out and Music is playing! Thanks again.

runeight · Apr 5, 2009 at 5:04 AM

sachu · Apr 5, 2009 at 7:36 AM

Quote:

Originally Posted by tacitapproval /img/forum/go_quote.gif
Success!! Voltages check out and Music is playing! Thanks again.

awesome..congrats on getting the amp going so quick!!

tacitapproval · Apr 5, 2009 at 1:38 PM

After a little sleep, the amp seems to run 12au7a at 12.6v with no problems, but the e12 keeps tripping on 6n1p-ev set at 6.3v. I managed to get music for a moment before the e12 cut out. I also tried two different tubes to make sure it wasn't a bad one.

edit: 12bh7a works as well.

runeight · Apr 5, 2009 at 2:33 PM

Are you using the stock C4L and C4R??

Also, please check the values of R1E, R2E, and R4E.

Thanks.

tacitapproval · Apr 5, 2009 at 2:47 PM

For c4, I am using the wimas Wiatrob offers as an upgrade.
The e12 resistors check out ok.

Giuss · Apr 5, 2009 at 2:56 PM

Where to find constant current diodes?

Is possible to use another solution? Like LM334 or discrete solution for constant current?

Bye

runeight · Apr 5, 2009 at 3:16 PM

Hi Giuss. I specifically used CRDs to save space. Did not attempt at all to create an alternative to them.

Tacitapproval, we noticed some of this in one or two of the prototypes, particularly if someone used caps with long leads. But we made some adjustments and haven't seen it for a while.

Do you have other tubes to try? To see if the problem occurs with anything other than 6n1ps.

tacitapproval · Apr 5, 2009 at 3:21 PM

Those are the only 6.3v kind I have. I have several 12.6v versions, which so far have all worked.

None of my caps have extended leads, but I could reflow them if it might help?

edit: I just tried a third 6n1p and it is playing ok. I guess this may be a problem with the other tubes. Good thing I have a few of these.

runeight · Apr 5, 2009 at 5:02 PM

Great. So you are ok now?

runeight · Apr 5, 2009 at 5:59 PM

Quote:

Originally Posted by Giuss /img/forum/go_quote.gif
Where to find constant current diodes?

Is possible to use another solution? Like LM334 or discrete solution for constant current?

Bye

I guess to suggest the obvious, and not necessarily to push the products, but if you were to buy a kit you would get all the necessary components.

Latest Thread Images

runeight

Member of the Trade: Cavalli Audio

tacitapproval

100+ Head-Fier

runeight

Member of the Trade: Cavalli Audio

runeight

Member of the Trade: Cavalli Audio

tacitapproval

100+ Head-Fier

runeight

Member of the Trade: Cavalli Audio

sachu

Headphoneus Supremus

tacitapproval

100+ Head-Fier

runeight

Member of the Trade: Cavalli Audio

tacitapproval

100+ Head-Fier

Giuss

New Head-Fier

runeight

Member of the Trade: Cavalli Audio

tacitapproval

100+ Head-Fier

runeight

Member of the Trade: Cavalli Audio

runeight

Member of the Trade: Cavalli Audio

Users who are viewing this thread