[richidoo]

I have replaced the stock heatsink with this one:
Mouser part #567-547-95AB  Wakefield DC/DC Conv QUARTER BRICK VERT.    $9.95

The chip's thermal protection is effective, and it will kick in quickly in when the chip gets hot. The heatsink is a noticeable improvement, the amp doesn't clip as quickly as with stock heatsink which doesn't touch the hot part of the chip. It runs much cooler now, so I hope it will last longer.
Pics in my gallery:

Rich

[tanchiro58]

The chip's thermal protection is effective, and it will kick in quickly in when the chip gets hot. The heatsink is a noticeable improvement, the amp doesn't clip as quickly as with stock heatsink which doesn't touch the hot part of the chip. It runs much cooler now, so I hope it will last longer.

Yes it is absolutely true. Thanks Rich for your help. I think it is a remarkable tweak and would make my music more resolution. 

[anubisgrau]

tan,
now i found some of your previous posts on this subject:

"I have modded both Altmann Attraction DAC (coupling ASC oil caps
100mF/375V $20 each and bypassed caps Mundorf Silver/oil .1mF/800V $18
each) and BYOB amp (coupling caps Sonicap GenI 10mF/1200V $20 each and
bypassed caps Jensen PIO .47mF/630V $40 each). "

i'm planning to mod BYOB. i'm wondering how did you chose these values. the voltages chosen looks far too high IMHO, maybe i'm wrong but i think there is no need to go for 1200V and 800V caps. there is no that much voltage in BYOB.

cheers gordan

Texendo,

It is all about DIY. As I know the previous Attraction DAC's owner is medical equipment's engineer and he did the modifying. Basically he just removed the wima coupling caps, filter caps and relay in the stock DAC. Then he got the ASC oil caps 100mF/375V to put in the place of the wima. He also added to the spruce board with a plywood (painted black in picture) and three BRD cones to hold the huge ASC caps and the original DAC.

My parts I modded are two Mundorf Silver/Oil 0.1mF/800V to bypass the ASC oil caps and a Jensen electrolytic 10,000mF/25V to bypass the 12VDC PS from battery using as a booster and filter. And I modded my BYOB amp from the stock one. Any questions I will be happy to answer.



Tan

[tanchiro58]

i'm planning to mod BYOB. i'm wondering how did you chose these values. the voltages chosen looks far too high IMHO, maybe i'm wrong but i think there is no need to go for 1200V and 800V caps. there is no that much voltage in BYOB.

Hi Gordan,

I just have some unused values of capacitors in hand at that time. Therefore, I used them and the caps have reasonable prices except the Jensen PIO. I did not pay attention to the voltage of the caps unless the values are not less than the stock one. Sonicaps have 10mF are little too high (it is okay using them)  but they are excellent to have a crispy details and Jensen added the sweetness and smoothness. Good luck.

Tan

[anubisgrau]

i'm planning to mod BYOB. i'm wondering how did you chose these values. the voltages chosen looks far too high IMHO, maybe i'm wrong but i think there is no need to go for 1200V and 800V caps. there is no that much voltage in BYOB.

Hi Gordan,

I just have some unused values of capacitors in hand at that time. Therefore, I used them and the caps have reasonable prices except the Jensen PIO. I did not pay attention to the voltage of the caps unless the values are not less than the stock one. Sonicaps have 10mF are little too high (it is okay using them)  but they are excellent to have a crispy details and Jensen added the sweetness and smoothness. Good luck.

Tan

OK that's what i've thought. i was quite surprised for such a high values for such a low power amp... thanks for claryfying it.

[Occam]

Tan,

I have modded both Altmann Attraction DAC (coupling ASC oil caps
100mF/375V $20 each and bypassed caps Mundorf Silver/oil .1mF/800V $18
each) and BYOB amp (coupling caps Sonicap GenI 10mF/1200V $20 each and
bypassed caps Jensen PIO .47mF/630V $40 each).

From your signature line, I'm assuming that the Altman Dac is the only source you've connected to your Altman amp. If so, you might want to consider a walk on the 'wild side' 
As you're presently configured you have the two sets of coupling caps in series, which you really don't need, though they do serve as both belt and suspenders.
You can actually ditch the DAC's output coupling caps, but only after you've repeated this mantra 1,000 times.
Turn the DAC 'on' connected to the 'off' amp. Only THEN turn on the amp.

Turning the components off is not order sensitive.
Assuming you'll actually remember to do this is optimistic. Inevitably, you'll forget to do, at least once.  The result will vary from a thump to a thwack and possibly blowing your speakers out.

[anubisgrau]

Is there any way to measure the parts with erased info?

[tanchiro58]

Turn the DAC 'on' connected to the 'off' amp. Only THEN turn on the amp.

Occam,

Yes that is what I did all the times. Thanks for the tip.

Is there any way to measure the parts with erased info?

Was it erased mF or voltage? if mF then you need a capacitor sorting meter like this one:



Tan

[anubisgrau]

a delivery of my new speakers is delayed which gives me a bit more time to think.... most likely the first thing i will do is to fully bypass the current volume pot and to run it with a fixed output - with a TVC preamp. in case this works better, than i might take care to build a dedicated unit that would utilize a TVC pre with multi inputs with BYOB as a power section, with modded output caps.

[anubisgrau]

a delivery of my new speakers is delayed which gives me a bit more time to think.... most likely the first thing i will do is to fully bypass the current volume pot and to run it with a fixed output - with a TVC preamp. in case this works better, than i might take care to build a dedicated unit that would utilize a TVC pre with multi inputs with BYOB as a power section, with modded output caps.

would anyone care to comment what there should be done to fully bypass a volume pot - it's blue alps i think. do i need to place a resistor instead or....? if yes how to define a value?

in case this could be done i would plug a TVC pre into the BYOB inputs to get a flavour how a TVC synergize with it. if they work good - better than with blue alps - i would also bypass the input connectors and wire the TVC directly into the BYOB.