Overhauling my Crack (Worklog) + a Few Questions

bloodhawk · 2008

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Offline bloodhawk

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on: November 30, 2017, 08:21:43 PM
Hiya fellas!

Been a lurker here for a while now, finally created an account last month, and about time i posted something.
Its about time for me to overhaul my crack with some really nice (albeit, definitely not super dooper necessary) , figured id post my work log of sorts - i.imgur.com/NX6vtYB.jpg

Most of the parts arrived last week, a few regrettable extras coming in next week as well ,along with my long anticipated TKD 2CP2511 arriving in another 10 days or so. However in the mean time, the awesome @Maxhawk hooked me up with the Speedball combo PCB along with the 5687 switch board.

Ill basically be overhauling things in stages, so that i can properly gauge what components result in what type of benefits, and quickly take something out if i dont like it -

Stock Crack w Speedball  - i.imgur.com/w7MhEir.jpg

Stage 1 -

A- Speedball board swap with the driver tube switch along with adding the 5687 switch board. Already soldered the components on the respective PCB's - i.imgur.com/cN1ZsYI.jpg i.imgur.com/fmTTEKl.jpg

B - Going to rewire the whole setup with 20AWG 600V silver plated copper wire. (This is more of my obsession with having the wiring super neat and clean)

C - Swap out the stock potentiometer with the Blue Velvet until the TKD gets here.

D-  Aluminium volume knob.

E- Add Resistors to the pot.

Stage 2 -

A- Swap out the Output Caps with 100uF 250VDC Mundorf MKP Caps. -  i.imgur.com/epFaRo9.jpg

B- Bypass the last power cap. with a 2.2uF 400VDC Clarity Cap MR (Might replace the default electrolytic cap with a better 220uF cap or a 100uF after i install the Choke)

Stage 3 -

A- Bypass the Output caps with 1uF 400VDC Audyn Copper Caps.

B - Bypass the remaining power caps with 2.2uF 250VDC Mundorf MKP's (Im highly skeptical this will result in any changes, but ah well, i have a few of these 1uF and 2.2uF MKP's, let me know if any one wants them. Just pay shipping / send me a shipping label and ill drop em off )

Stage 4 -

A - Add the Choke.

B- Add Cree Diodes.


 
Fingers crossed :P

« Last Edit: December 01, 2017, 07:00:01 AM by bloodhawk »



Offline bloodhawk

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Reply #1 on: December 01, 2017, 05:45:38 AM
One question i had with regards to the last power cap, once the choke and diodes are installed. Is it ok to replace the last 220uF cap with a 100uF 250VDC cap and maybe bypass that? (Provided they fit obviously)



Offline bloodhawk

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Reply #2 on: December 03, 2017, 09:54:56 AM
Progress.

Tested with the stock caps.. the DSB board the 5687 switch working perfectly with the voltages checking out.

Hit a slight snag with my drill going kaput , but JB Plastic weld epoxy to the rescue. Works perfectly! (Make sure to dry / cure over night)

Waiting on someone to reply to my rectifier bridge question now :(



Offline bloodhawk

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Reply #3 on: December 03, 2017, 03:00:04 PM
So been testing things all day -

A - Mundorf 100uF Caps - Wew instant jump in clarity

B - Choke + Rectifier Bridge - Didnt notice too noticeable a difference IMO. It could be just me, but i can hear a tiny bit more in the higher end? With a slight bump in Clarity

C - Bypass 100uF Mundorf MKP's with Audyn Copper 1uF  - WOW? !!! The sound stage feels a bit more expanded. Low end is much more tighter. The rumble is still there (like sub bass rumble) But the roll off is much more defined and the bass feels tighter overall.



Offline Depfa

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Reply #4 on: December 04, 2017, 07:52:29 AM
Very interesting progress.
Saved pics and text to hdd, just in case.

Can you also mention approx. price of parts you bought?

regarding the
Quote
Is it ok to replace the last 220uF cap with a 100uF 250VDC cap and maybe bypass that (Provided they fit obviously)

I think this: in theory, the power caps holding energy waiting for when it will be needed the most. And thats when bass drops. Low freq draws most power, while higher frequencies are soursing much less power comparatevaly. And the more loud volume you have the more evergy it sucks up. So, natively amp having 220uF x 3 times = 660 uF.
It was designed to have enough power stored to withstand heavy bass at high volumes.
So, unless you listen at deafening volumes, cranked up pot, i'd say, this cap swap is absolutely good to go, no worries.
Bypassing should benefit too.
Although people do not hear day night difference when upgrading power caps. Output caps is another story, as you just confirmed yourself. The most audible change is from them.

If you strive to make good power, here's another thing i noticed. Often each bridge diode is bypassed with small individual cap. For example, see AMB σ22 power supply board scheme at his site. (those PSUs are used in b22 amplifier). Notice the bypass caps at each diode.



Offline bloodhawk

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Reply #5 on: December 04, 2017, 08:02:05 AM
Very interesting progress.
Saved pics and text to hdd, just in case.

Can you also mention approx. price of parts you bought?



About $150 for all the caps + Speedball/5687 Switch board and the necessary components.
And another $75 for the TKD 2CP2511 (Should be here next week).

I will be cleaning up the setup even more this week, the current setup was to test out everything before i set things up for the long run. And im glad i did this because i found that one of the 5687 Blue LEDS's was dead. So that needs to be replaced. Plus this gave me a much better idea of spacing, so now i can better design my second face plate.


I think this: in theory, the power caps holding energy waiting for when it will be needed the most. And thats when bass drops. Low freq draws most power, while higher frequencies are soursing much less power comparatevaly. And the more loud volume you have the more evergy it sucks up. So, natively amp having 220uF x 3 times = 660 uF.
It was designed to have enough power stored to withstand heavy bass at high volumes.
So, unless you listen at deafening volumes, cranked up pot, i'd say, this cap swap is absolutely good to go, no worries.
Bypassing should benefit too.
Although people do not hear day night difference when upgrading power caps. Output caps is another story, as you just confirmed yourself. The most audible change is from them.

If you strive to make good power, here's another thing i noticed. Often each bridge diode is bypassed with small individual cap. For example, see AMB σ22 power supply board scheme at his site. (those PSUs are used in b22 amplifier). Notice the bypass caps at each diode.


Gotcha, im probably going to end up bypassing the last power cap first with a 2.2uF Clarity Cap MR to see what type of difference it makes. I have read a lot of mixed feedback about bypass the last power cap. The other 2 power caps im bypassing using 2.2uF Mundorf MKP though to clean things up further.
Depending on how the last power cap bypass goes, i might just outright replace it with a better film cap in the future.

Right now i need to find a loose connection / solder joint that is causing a bit of fine crackling noise every time i tap the chassis.