legarem:
thanks as always, i have some bradleys carbon comp 1/4 watt 100R's on the way....
i guess i feel that the dac is lacking bass and presence, warmth but like i said... i have not connected the transformers to ground..
by the way, do i need to have the dac connected to mains supply earth in order for it to acheive a ground from the analogue selection? I guess not, and could you tell me where on the pcb you chose to take your analogue ground point from?
cheers stuart
thanks as always, i have some bradleys carbon comp 1/4 watt 100R's on the way....
i guess i feel that the dac is lacking bass and presence, warmth but like i said... i have not connected the transformers to ground..
by the way, do i need to have the dac connected to mains supply earth in order for it to acheive a ground from the analogue selection? I guess not, and could you tell me where on the pcb you chose to take your analogue ground point from?
cheers stuart
I just came across this thread and am very impressed with your success with the transformer outputs. I have a Zhaolu 2.5C which also uses the CS4398 DAC chip. I've been playing with all sorts of output topologies on my Zhaolu and have not been totally satisfied. it always seems to sound strident on loud passages using op-amps.
I am very tempted to try the transformer route (don't know why I didn't think of that myself, since I've used them successfully in the past). Thanks for the reawakening guys.
Anyone have a final word on the inexpensive Edcor's (XSM600/600 would be the best model I assume) to see if their sound is decent, rather than dropping 2x-4x on the more expensive options? Which models of each are recommended (Lundahl, Studor, Tamura, Digitec, etc.)?
Thanks,
Bob
I am very tempted to try the transformer route (don't know why I didn't think of that myself, since I've used them successfully in the past). Thanks for the reawakening guys.
Anyone have a final word on the inexpensive Edcor's (XSM600/600 would be the best model I assume) to see if their sound is decent, rather than dropping 2x-4x on the more expensive options? Which models of each are recommended (Lundahl, Studor, Tamura, Digitec, etc.)?
Thanks,
Bob
BobM said:
They are just first order filters to get rid of the nasties, the transformers themselves don't need a load, and you don't want to load down the chip output. The output impedance of the chip, which is around 120 ohms, will be reflected through the trafo, plus any series resistance you have on the primary. You should be able to drive any type of circuit with the output unless you place too much load on it with other resistors on the secondary.
Bill
Praudio said:Which models of each are recommended (Lundahl, Studor, Tamura, Digitec, etc.)?
We all waiting Legarem sonic description
I know that many peoples are waiting
This is scheduled later for these reasons
- I'm now often outside for my job with long working weeks
- It is summer time (or at least supposed to be here)
- I bought a Mac Mini to use as a music server with the system and i have to do many tryings
All this means that i lack time but I will do it later
I worked tonight with the two resistors at the primary of the transformers.
The Lundahls seemed to give better bass than the Tams but the load reflected by the Lundahls is higher than the Tams.
I changed the 100 ohms in the primary of the Tams for 210 ohms Allen Bradly CC resistors.
The difference in the bass is night and day. It is now as good or better than with the Lundahls
The capacitor is now .007 uF (7nF or 7000 pF) with the 210 ohms resistors.
This means that the CS4398 will lack bass if loaded too much. As it's output impedance is 120 ohms, a load of 1200 ohms (10X) could to be great.
600 ohms (Tams)+ 210 + 210 = 1020 ohms
Maybe a little bit higher than 1020 ohms to reach 1200 ohms should be the best.
I'll do the same with the Studer uncapsulated.
The Lundahls seemed to give better bass than the Tams but the load reflected by the Lundahls is higher than the Tams.
I changed the 100 ohms in the primary of the Tams for 210 ohms Allen Bradly CC resistors.
The difference in the bass is night and day. It is now as good or better than with the Lundahls
The capacitor is now .007 uF (7nF or 7000 pF) with the 210 ohms resistors.
This means that the CS4398 will lack bass if loaded too much. As it's output impedance is 120 ohms, a load of 1200 ohms (10X) could to be great.
600 ohms (Tams)+ 210 + 210 = 1020 ohms
Maybe a little bit higher than 1020 ohms to reach 1200 ohms should be the best.
I'll do the same with the Studer uncapsulated.
cases to house the DAC
I have a few question, if somone could be kind enough to answer it would be great.
1. Can anyone recommend some URLS that I can get a case for the DAC, was going to just put it in an external CD case but probably not ideal.
2. Is there anyway that you can somehow get the DAC to show what signal its receiving i.e 44kbps or 92kbps
3. can someone please explain why most implementations of this DAC and MODS of others, seem to to NOT use the DACS analogue out and add there own ??are the DACS analogue outs and Digital ins inferior.
Thanks
I have a few question, if somone could be kind enough to answer it would be great.
1. Can anyone recommend some URLS that I can get a case for the DAC, was going to just put it in an external CD case but probably not ideal.
2. Is there anyway that you can somehow get the DAC to show what signal its receiving i.e 44kbps or 92kbps
3. can someone please explain why most implementations of this DAC and MODS of others, seem to to NOT use the DACS analogue out and add there own ??are the DACS analogue outs and Digital ins inferior.
Thanks
data said:
7.5-9.5V will do fine for the digital supply if it's rated for 1A or more.
Ebay is your best bet for trafos if you're looking for deals. Shipping from the States is probably expensive, don't know for sure. I have a pair of Jensen JT-123 I could sell but I have no idea what it would cost to ship them.
Best, Bill
Re: cases to house the DAC
1. GOOGLE is your friend, search (diy audio case).
2. Not without extra circuitry, but I'm sure it can be done. You need a digital guru for this one, try posting a new thread.
3. Personally, I just don't like opamp chips, don't have one in my entire system. Every one sounds different and none sound good to me. They all use outrageous amounts of negative feedback.
The digital input is OK without the pulse trafo, but the RC circuit on the board is not the recommended value from Crystal, easily changed. It's covered in the first few pages of this thread.
Best, Bill
shuggi67 said:
1. GOOGLE is your friend, search (diy audio case).
2. Not without extra circuitry, but I'm sure it can be done. You need a digital guru for this one, try posting a new thread.
3. Personally, I just don't like opamp chips, don't have one in my entire system. Every one sounds different and none sound good to me. They all use outrageous amounts of negative feedback.
The digital input is OK without the pulse trafo, but the RC circuit on the board is not the recommended value from Crystal, easily changed. It's covered in the first few pages of this thread.
Best, Bill
Re: cases to house the DAC
For the case, you can go here. The aluminum cases are great. Shipping is fast.
http://stores.shop.ebay.ca/Antek-inc__W0QQ_armrsZ1QQ_fsubZ5
shuggi67 said:
For the case, you can go here. The aluminum cases are great. Shipping is fast.
http://stores.shop.ebay.ca/Antek-inc__W0QQ_armrsZ1QQ_fsubZ5