[Samgotit]

Quote:

Originally Posted by tilt wouldn't it be better to leave the dac at v6, and just change the IV's to 160ohm. The TDA1543s get pretty hot at 6v, i'd hate too see them at 8. Also, does heat shorten the life of the chips. Would ram sinks help? either way, LM7808's are on the way

That's a good question.

Being generally ignorant on the subject I am operating on the assumption that bigger is better

. More voltage sounds good to me. Absolute max is 9V. I've seen many other TDA1543 based DACs using 8V.
See this:
http://www.dddac.de./
http://www.geocities.com/TDAC1543/

Now that you bring it up heat concerns me too. We can always get taller sinks, cut a hole in the top, and give it the smoke stack look. We can order these the same time we order new facny resistors for IV and Vref (or trim pot).

The other consideration is Vref. By increasing supply voltage Vref can increases as well up to 2.30V. Again, whether bigger = better I have no clue.

In the end the supply voltage will probablly not matter as much as getting quality I/V resistors and matching/adjusting Vref. I'm considering simply replacing the trim pot for Vref with a Bourns form Mouser for now. Still don't know what value to use though.

Sam

 

[tilt]

Argh! i came home to see a sticky note from purolator on the door. If they don't come by again i'll pick them up tomorrow. I'll replace the regs first and do a quick a/b. Then the caps near the regs, then all the 0.1uf's.

Im not sure what you mean by Vref. What IV resistors are you thinking of getting?

 

[tilt]

For the IV maybe some new old stock Shinkoh Tantlums?

Dsavitsk, i read on one of your other posts about a "maxed out DAC" using Riken's as I/V's. Is that personal preference or just something you have easy access too?

 

[Samgotit]

Quote:

Originally Posted by tilt Argh! i came home to see a sticky note from purolator on the door. If they don't come by again i'll pick them up tomorrow. I'll replace the regs first and do a quick a/b. Then the caps near the regs, then all the 0.1uf's. Im not sure what you mean by Vref. What IV resistors are you thinking of getting?

For I/V I ordered Holco from mouser:

Mouser# 279-274
http://www.mouser.com/index.cfm?hand..._pcodeid=02040

Sam

 

[dsavitsk]

Quote:

Originally Posted by Samgotit For I/V I ordered Holco from mouser:

I think these are the new versions with steel end caps. They are generally not considered any good. You need to find NOS Holcos.

Quote:

Originally Posted by tilt Dsavitsk, i read on one of your other posts about a "maxed out DAC" using Riken's as I/V's. Is that personal preference or just something you have easy access too?

Yes. Peter Daniels at DIYAudio.com suggested them, and I agree that they are a good choice. I also like Kiwames, though I am not sure I'd recommend them. The sound is a bit soft and pillowey, but kind of nice. I've also had decent luck with PRPs. Truth is, I haven't tried anything that was terrible, just a few things that were a lttle better. If you look elsewhere, you'll see that Rick likes Vishay Bulk Foils. I've not tried them, thought.

 

[Samgotit]

Quote:

Originally Posted by dsavitsk I think these are the new versions with steel end caps. They are generally not considered any good. You need to find NOS Holcos.

Darn, I vaugley remember reading that here. It slipped my mind when I ordered them.

Given this, I think it would be a good idea to socket these resistors. Different values and different types all day long. Would really be nice to do some of the comparisions on my own ears.

Mouser# 575-113120 for the pins
http://www.mouser.com/index.cfm?hand..._pcodeid=57508

 

[tilt]

The BASS! she has returned!!!

pics comming soon
-----

2 LM7808
2 Panasonic FM 1000uf
8 BC Components Polypropylene Film 0.1uf

I/V Resistors had to be moved to the underside of the board to make room.

 

[shlomomofo]

kewl!!! was it easy to put in the new regulators?

 

[Samgotit]

Quote:

Originally Posted by tilt The BASS! she has returned!!! pics comming soon ----- 2 LM7808 2 Panasonic FM 1000uf 8 BC Components Polypropylene Film 0.1uf

She's the most beautiful thing I've ever seen! How did the desoldering go?

Quote:

I/V Resistors had to be moved to the underside of the board to make room.

There goes the socketed I/V restitors.

Ok tilt, you need to get on to reclocking and stacking 8 more DACS

.

 

[shlomomofo]

Quote:

Originally Posted by Samgotit reclocking and stacking 8 more DACS

wha?? can you seriously just start stacking up more dac chips in this design? i know that in the dddac1543 mk2, you can have multiples of 12 dac chips. man that would be sweet. and what is this about reclocking?

this is very awesome, but sadly (not really.

) i'm going to be away from home (in the USA) for at least a few months. i'll be sure to look this thread up when i get back... i'm sure i will have a lot to do to catch up! good luck with the new mods.

 

[Samgotit]

Quote:

Originally Posted by shlomomofo wha?? can you seriously just start stacking up more dac chips in this design? i know that in the dddac1543 mk2, you can have multiples of 12 dac chips. man that would be sweet. and what is this about reclocking? this is very awesome, but sadly (not really. ) i'm going to be away from home (in the USA) for at least a few months. i'll be sure to look this thread up when i get back... i'm sure i will have a lot to do to catch up! good luck with the new mods.

I would not even no where to start with reclocking

.
Here is a"Pro" Reclocking mod:
http://www.effectiveaudiomod.com/Comp_LiteDAC.htm

I think you can stack as many chips as you like with the right power supply. LM7808 is rated for 1A. 16 chips would use 60mA*16 = 0.960mA/2 regulators, so I think we would be OK. Change I/V and Vref to match. Of course, I'm sure the are other variables I'm not aware of, but it may be an option. Sure would be fun. Whether it's worth it is the queston.

Sam

 

[tilt]

oooo! stacking, i like it!

 

[tilt]

Quote:

Originally Posted by shlomomofo kewl!!! was it easy to put in the new regulators?

Regs were a bit tricky.

It would have been easier with a little 20w iron and a needle tip.

when i first put it in, the bass seemed a little boomy, but even now i can hear it start too tighten up. Its also probably because i was used to the recessed bass from before. I think it will compliment the K701's (supposed to have weakish bass) If they ever arrive, sigh

 

[tilt]

Quote:

Originally Posted by Samgotit That's a good question. Being generally ignorant on the subject I am operating on the assumption that bigger is better . More voltage sounds good to me. Absolute max is 9V. I've seen many other TDA1543 based DACs using 8V. See this: http://www.dddac.de./ http://www.geocities.com/TDAC1543/ Now that you bring it up heat concerns me too. We can always get taller sinks, cut a hole in the top, and give it the smoke stack look. We can order these the same time we order new facny resistors for IV and Vref (or trim pot). The other consideration is Vref. By increasing supply voltage Vref can increases as well up to 2.30V. Again, whether bigger = better I have no clue. In the end the supply voltage will probablly not matter as much as getting quality I/V resistors and matching/adjusting Vref. I'm considering simply replacing the trim pot for Vref with a Bourns form Mouser for now. Still don't know what value to use though. Sam

K, i wanna replace the vref too... what should i use? (if i were to use a resistor)

 

[Samgotit]

I replaced the trim pot with a 1k bourns. I adjusted the resistance to give me a Vref of 2.20V. I cannot tell a difference in sound. Sadly, this is all I've had time to do. I really need to get to the bigger stuff.

Shlomomofo did the calculations earlier for replacing the Vref trim pot with a resistor. I came up with the same numbers. I Do NOT know if they are right.

Cheers,
Sam