Pumpkin preamp - More Boring Making Thread

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#461
Re: Re: Re: Re: Re: Re: Inductor DIY

Magura said:





Naah, just trying to meet his target😀

Once he becomes more familiar with winding, bifilar wound air cores would be the ticket.

Anyhow, the real easy solution would be ferrite core, like used for SMPS, those can carry like 1A a piece, offers like 3mH for the size of a 5W resistor. Cost like 1 ot 2 USD, so 2 in parallel should cut it.


.......but he wanted to wind his own, and he wanted low DCR 😎


Magura 🙂
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anyway - he can look for SP300B posts - he made common mode chokes for Shunty ; they are easy visible on pics
 
#463
Sorry, wrong pic......

🙂
 

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#464
Hi Guys,

I got things working. I had a quick listen, it is one amazing amp.:smash: 😀 No doubt about it.

I had originally sized my cabinet for one trafo, it is a 14" Par-Metal cabinet. Due to my trafo problems mentioned earlier, I am now using 4 trafos. This eliminated the space inside the cabinet pushing one channel right up alongside shunty and very close to the trafos. Not surprisingly this channel has a pretty big hum:xeye: If I removed the board amd let it hang outside the box putting some space between board and the supply the hum reduces. It looks like either I have get a new and bigger cabinet or take the trafos out and put them in a smaller cabinet and make a 2 box system.

Can anybody suggest some inexpensive cabinets?? Or could this be solved other ways??

🙄 So close, yet so far.:bawling:
 
#466
I'm just looking at steen's pics ....... in hope that I can find some adequate pic for dviswa but - naah ........ steen have just two xformers , potted , and Shuntys are between them and Pumpie pcbs ......

anyway 😉 , I'm just laughing ....... look at this drek - all that but only 4 active devices per channel (two per leg ) .... ! :rofl:
 

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#467
ZM,

Obviously. I am not in the same league as Steen and have no desire to compete with a master 😀

I am using the Mercury Magnetics TA110-W from ApexJr. 2 Trafos per channel. I also noticed these trafos do produce a good bit of audible hum, the Magnetostriction vibration variety. I tried tightening the screws down to stop the vibration, not much use. Don't know what trafos Steen is using. I am not too keen of pottig the trafos myself 😉. Surely, the trafo vibration is another thing I need to fix. Any ideas on how to dampen the trafo vibrations down?

Dinesh
 
#469
dviswa said:
ZM,

Obviously. I am not in the same league as Steen and have no desire to compete with a master 😀

I am using the Mercury Magnetics TA110-W from ApexJr. 2 Trafos per channel. I also noticed these trafos do produce a good bit of audible hum, the Magnetostriction vibration variety. I tried tightening the screws down to stop the vibration, not much use. Don't know what trafos Steen is using. I am not too keen of pottig the trafos myself 😉. Surely, the trafo vibration is another thing I need to fix. Any ideas on how to dampen the trafo vibrations down?

Dinesh
Click to expand...


naah ....... steen is master scavenger , even if he certainly put nice gross of greenies in his scavenging 😉

(steen is my man !)

put these buggers in bucket of varnish or glue or paint ; let them soak for 30mins and pull them out ; leave them overnight in outdoor and pray 😉

nothing better than separate box for noisy xformer ( or noise inducing , whatever )

mumetal will help just a little , if trouble with them is already apparent .
 
#478
Re: Re: Re: Hi!

zeonrider said:


Familiar with ???, don't tell me that you have the same, or Iam wrong.It is jus 1U, & for A5 I preparing 4 pcs.5U.

Regards zeoN_Rider
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Take a look at Steenoe's AX, or Lykkedk's F4, then ask them where they got them from 😀

They don't offer much cooling in 5U, 2U (180mm) seems to be where it all turns into a self heating heatsink.


Magura 🙂
 
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