After reading trough the entire thread (I might have missed a few pages here and there due to fatigue...) and while doing so I've cobbled together a small doc with some images of advised mods and what they should look like.
Posting it here for everyone who's interested. Credits go to all the folks who actually did the research and made the images; thanks for all the great input and ideas
(Sorry for the zip, but Im not allowed to upload the 400kb PDF...)
Some additional mods you might try:
1. Replace the power caps by multiple low ESR caps. Multiple low ESR caps give an extreme low ESR when paralleled together.
2. Remove the dip switches, as turning them on will degrade the sound, and when turned off, why not remove them?
3. Dont touch the caps at the 5v line, as the LM317 does not like lower ESR. You might mod the cap at the 32v line there though.
4. The zalman NB47J is a good heath sink, but if you want to stick with the fan: make an additional 5v supply (might even be out of an 7815 regulator, they cost virtually nothing) (dont use a big resistor, it will still pollute your rails)
5. About rewiring the pins: Sure did not provide me with any information when I asked them. As Elfishi reported no change in heath production, leave it be. It is kinda hard to solder there.
6. If you use a 350w meanwell power supply, you might want to connect the COM and the GROUND on them (might be better to use a 100k resistor paralleled by a 1uF cap or something), as this is reported to reduce the noise the psu makes. Also note that if you do this, and have the earth connected to the PSU, you might get ground loops. Disconnecting the ground on the meanwell fixes this.
7. Mod/replace the fan in the meanwell supply. It is reported to be very noisy.
8. Keep wires from the pot to the input short, very short.
9. Might be worth to check out a soft start made on an italian forum. I dont have the link, but I might provide you with the schematics when you email/pm me. It can also be used to power the amp on and 1 second later disable the mute. (less pop-on noise)
10. As said before, remove the suppressors, stock input caps, the 22k that connect the input to ground, replace the input caps, replace the output coils, and modding the power supply traces.
Repacing the output caps however requires some things, as the leads will function as antennas. Buy some good caps that fit right in the original space, or leave them be. They dont compromise the sound that much.
One last thing: I noticed adding some different values of film caps across the 32v line (to ground) reduced a little bit of the noise. Now the noise is barely audible when i put my head practically inside the tweeter.
I hear that the panasonic FM's are great.
You might want to check out what capacity still fits. I think 820uF panny FM will fit, but I havent tried them yet.
They are very affordable too.
All the mods, and some more that can be done to the 2 channel boards, can also be done to the 4 channel, but you might want to check out the 4 channel tread. (yes, there is one)
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Which coil?
What is the Wurth number of the coil you are using? It must be a different model than I am using as the WE-PD XXL doesn't come in 3.9 .
In the pile
I had the 3.9uH coils on the amp for a couple days but decided to go back to the WE-PD. I don't recall them getting anything like hot enough to draw my attention.
I had the 3.9uH coils on the amp for a couple days but decided to go back to the WE-PD. I don't recall them getting anything like hot enough to draw my attention.
Hi. Guys.
I have a question to all of you who compared these Tripath's to Solid State's.
I currently have Rotel RA-980BX, wich is overall very good but too harsh. I also own Hlly T-amp based on TA2022, wich I'm very disapointed with. It lacks bass controll and calrity and openess of highs and mid's.
Is it somehow possible to modify this Sure amp to match Rotels controll on bass and get clear and smooth mid's and high's with really big soundstage.
I'm driving quite difficult setup wich are 2 paralell 12" Audax woofers in Open Baffle per side (qts 0,8) and I need then controlled.
PS. This Rotel's damping factor is DF>1000 !
I have a question to all of you who compared these Tripath's to Solid State's.
I currently have Rotel RA-980BX, wich is overall very good but too harsh. I also own Hlly T-amp based on TA2022, wich I'm very disapointed with. It lacks bass controll and calrity and openess of highs and mid's.
Is it somehow possible to modify this Sure amp to match Rotels controll on bass and get clear and smooth mid's and high's with really big soundstage.
I'm driving quite difficult setup wich are 2 paralell 12" Audax woofers in Open Baffle per side (qts 0,8) and I need then controlled.
PS. This Rotel's damping factor is DF>1000 !
Red herrings, in my experience. Tying COM and GROUND made no difference in my listening environment (not that my experience is absolute, mind you), while I'm even more skeptical about messing with the power supply's fan. I would think you might need to address your power delivery needs if the fan comes on for any appreciable amount of time--you're pushing its limits, and possibly compromising dynamic headroom. If the fan came on regularly, I'd be looking for a better solution--a bigger power supply.
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dr_vega, I tried out those caps you gave me, and they sounded, um, different. Not better or worse, but I have to give them more time in order to properly evaluate them and perhaps adjust to them. Still a pleasure to listen to, though. More later . . . and thanks!
Leave the tank caps on
Leave the stock tank caps on. They are excellent. Add more capacitance if you like. Panasonic, Elna ect.
4X100 thread
.
http://www.diyaudio.com/forums/clas...ath-board-4-100w-class-d-amplifier-board.html
Check on the 4X100 thread.
.
http://www.diyaudio.com/forums/clas...ath-board-4-100w-class-d-amplifier-board.html
How much capacitance do you have on your rails these days? I have 1000uF on each channel, if I'm not mistaken. I don't have a soft-start implementation, and I'm trying to avoid damaging turn-on transients. But I'd like to push for more capacitive reserves, so to speak.
More power
You may want an amp module with more power. Maybe something like the 3020 from 41Hz or Connexelectronic. Or even one of the big AB amps from Connexelectronic.
Rail caps stock
I haven't changed anything on the power supply side of the circuit yet other than isolating the fan supply. The Meanwell will protect it's self if you add too much.
I haven't changed anything on the power supply side of the circuit yet other than isolating the fan supply. The Meanwell will protect it's self if you add too much.
power or dampig factor ?
Actually the woofer combination is difficult due to low impedance but not require lots of power. With 4.3 coil their about 95db/2.8v (92db/w)
Do I really need power to controll them or it's a matter of amp's construction (damping factor).
Are there any data about damping of class d amps ?
Actually the woofer combination is difficult due to low impedance but not require lots of power. With 4.3 coil their about 95db/2.8v (92db/w)
Do I really need power to controll them or it's a matter of amp's construction (damping factor).
Are there any data about damping of class d amps ?
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