DIY Audio Projects Forum

I have noticed that Mosfets found in power supplies IRF 530 630 and so forth will exhibit the quick hiss and also have a worse response curve. I am not 100% sure what is going on, just think it is something internal to the mosfet to prevent thermal runaway. If you are experiencing more than one hiss an hour then heatsinking is in order. It does not have to be fancy, I have used washers before.

For your power supply question download PSUD2 and design for least amount of ripple. http://www.duncanamps.com/psud2/index.html Some RC LC theory http://www.play-hookey.com/ac_theory/ps_filters.html

Now the only issue with low voltage power supplies is to really make them clean you will need very low value resistors, in turn they draw some current.

Other than that you can look up some 12v power supply projects by Ti Kan (AMB) http://www.amb.org/audio/sigma11/

You are correct, got a little happy in eagle with the flip button. It will get updated but may take a while.

Welcome to the boards.

the MOSFETs are heatsinked... and I noticed... if I fan the heatsinks... it gets cooler and sounds slightly better...

I am presuming the hissing does come from the power supply... I am thinking of making it away... I guess it is ripple in the supply... how do it away if it is ripple? I have 1000uf 50V capacitors in hand.

are you suggesting I put a very low value resistor at the power to remove them? in between the capacitors?

Ok guys i am an idiot... I bought polarized caps for the 2.2 uF caps(C1) and I was wondering, when they come in the mail, can I still use them? I dont want to have to buy more and pay more shipping for 60 cents worth of caps =| Stupid shipping lol

No problem, just remember the (+) always faces the tube.

So as an input coupling cap the music signal comes into the (-) and out the (+)

Welcome to the board!

Santik,

My suggestion at this point is to purchase a used SMPS that exibits low ripple. It may take some trial and error. Go to a thrift and pick up all the 12 and 13vdc smps you can find. They usually are only a few dollars or pounds. Once you get that working.

Review the Neeets module I linked earlier and study chapter 3, it covers power supplies and filtering.

Once you have a grasp it will all come a little easier. Not that do not want to answer your question, just this is a learning experience.

yeah, I understand. Will do.

Will see what I can do and tell everyone what I did to overcome it!

hi, this is my first post [found the project via google]
and this is also my first tube-based project

i've finished this project, it sounds great...but with some problem:
- too bright
- early clipping
- lack of bass

i'm using Electro Harmonix 12AU7 and 4k7 resistor [instead 10k pot]
how to fix that problem?

P.S: pic uploaded later
thanks

Post pics when you have a chance thanks

yes, C1 is 2.2uF electrolytic [but the + goes to input and - to the tube ] and it fries my laptop's soundcard

the [+] of C3 is 7.20v. is it means to use higher plate resistor value?

Pics: [sorry phone camera ]
outside


inside

a bit mess

freq. response attached [tested using friend's tascam us-122]

cheers