That has to do with your target voltage range. There are sizing examples in the Bib guide. Assuming you don't talk audio pots for dcb1. Bib is PSU.
I'd like to drive the output of my dac chip (ak4396) with the dcb1 buffer.
I'd be hooking it up to AOut L+/- & AOut R+/- .
The only note in the datasheet is in regards to "when AOUT drives some capacitive load, some resistor should be added in series between AOUT and capacitive load."
I haven't looked at the dcb1 buffer in a while, but I don't see it as being a problem. Just wondering if it's a good idea or not?
I'd be hooking it up to AOut L+/- & AOut R+/- .
The only note in the datasheet is in regards to "when AOUT drives some capacitive load, some resistor should be added in series between AOUT and capacitive load."
I haven't looked at the dcb1 buffer in a while, but I don't see it as being a problem. Just wondering if it's a good idea or not?
1st listen
Thanks to ZM's confirmation on my A3's question/suspicion. I was good to test tonight. I hook up my Audio-GD Ref-7 to DCB1 + step attenuator and then to A3. With no burn-in at all, the sound is definite quite different from Lighter Note + A3 or my Rotel RA-970BX.
It seems the bass is deeper and more relaxed. However, the mid/high was less sweet. It is definitely too early to tell and only with some standard parts. The good thing is that it is working. Thanks to T-B's kit and everybody's help!
However, after about 10 mins of listening, I start to hear some high freq faint noise (something like FM radio). Too tired to worry about it now.
Also, the MOSFET and heatsink was only about 3 deg C higher than ambient with moderate heatsink. I wonder why.
Thanks to ZM's confirmation on my A3's question/suspicion. I was good to test tonight. I hook up my Audio-GD Ref-7 to DCB1 + step attenuator and then to A3. With no burn-in at all, the sound is definite quite different from Lighter Note + A3 or my Rotel RA-970BX.
It seems the bass is deeper and more relaxed. However, the mid/high was less sweet. It is definitely too early to tell and only with some standard parts. The good thing is that it is working. Thanks to T-B's kit and everybody's help!
However, after about 10 mins of listening, I start to hear some high freq faint noise (something like FM radio). Too tired to worry about it now.
Also, the MOSFET and heatsink was only about 3 deg C higher than ambient with moderate heatsink. I wonder why.
An externally hosted image should be here but it was not working when we last tested it.
Stick another series resistor 220R in line with your RCA out, just in case you have an oscillation, because radio like whistle is suspicious. See if you will hear birdies again and what it does to the sonic. As for dissipation look if you still got your voltage drops across current set resistors intact, meaning that your currents are still on. If OK, being cool just means you got enough metal and you can go stronger bias even when you fancy.
Hi all
I've been reading this thread for a while
I'm on page 131 for now- its great!
Finished stuffing my board but did not connect to in/output
Vout is 10.13 & 10.20
V at 10R risistors 2.09 & 1.92
DC offset set at lowest reading (2M) shows 0.003 & 0.001)
Looks okay right? but mosfet are not getting warm at all- is this okay?
Thanks
IK
I've been reading this thread for a while
I'm on page 131 for now- its great!
Finished stuffing my board but did not connect to in/output
Vout is 10.13 & 10.20
V at 10R risistors 2.09 & 1.92
DC offset set at lowest reading (2M) shows 0.003 & 0.001)
Looks okay right? but mosfet are not getting warm at all- is this okay?
Thanks
IK
What do you mean lowest reading 2M? 2 millivolt scale on your DVM? If yes, then it measures fine all over. About heat depends on sinks. If you had bolted it to a thick chassis with big sinks it can be cool at 200mA and 10V you run. That 2V/10R=200mA has to go somewhere could not stay at CCS. Is any other component from the non sink ones suspiciously hot beyond the 7812?
Audio gains against cost gains here are neglidgeable.
I started with Salas shunt reg at about 60mA. It sounded brilliant with the standard B1.
Increasing current to 120mA didn't seem to bring any sonic benefits. But I had the heatsinks so I've left mine at 120mA.
All 600mA does, to me anyway, is roast the MosFets and increase the heatsink cost.
I did try it and, to me, it didn't sound any different.
I'm familiar with Ultra-Fi sound, but the Snake Oil vendors will disagree.
The 2E Maplin Heatsinks that I used are good to about 220mA, after that they need fan assistance.
The proof of the pudding is in the building.
Salas originally specified the Shunt Reg at about 60mA. And, I will support him to the end, it sounds BRILLIANT.
I started with Salas shunt reg at about 60mA. It sounded brilliant with the standard B1.
Increasing current to 120mA didn't seem to bring any sonic benefits. But I had the heatsinks so I've left mine at 120mA.
All 600mA does, to me anyway, is roast the MosFets and increase the heatsink cost.
I did try it and, to me, it didn't sound any different.
I'm familiar with Ultra-Fi sound, but the Snake Oil vendors will disagree.
The 2E Maplin Heatsinks that I used are good to about 220mA, after that they need fan assistance.
The proof of the pudding is in the building.
Salas originally specified the Shunt Reg at about 60mA. And, I will support him to the end, it sounds BRILLIANT.
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I did bring mine to slightly above 600ma and noticed improvement in the imaging. To me and my tin ears it was worth the cost of the two 2.5R resistors. Cooling is still good with the "Tea Bag" style heatsinks. I did replace the top of the metal case with a perforated aluminum sheet, just in case.
I've also been playing with the three 100uf caps. I've tried so far Slimic IIs, KZs, Cerafines (older and newer) and STD blackgates. I burned each for about 24 hours (some say not enough for the blackgates) and so far I like the Slimics the best. Compared to all the other caps they sound more defined and increased a bit the width/depth of the sound stage. They also strike a good balance between adding a tad more definition and brightness to the sound. I found the Cerafines were the least bright sounding of the lot, but their sound stage was not as well presented as the blackgates and Slimics. Compared to the Slimics, the blackgates sounded a tad brighter. The originally installed KZs I would rank as last in this pack for me.
All the caps were 24-63v except the blackgates, which I could only find 160v ones for a reasonable price.
Another change for me was to replace the 220k caddock resistors for naked foils (which I was able to afford after taking a second mortgage on my house...). I had already replaced the 220Rs with naked foils. This change opened up the sound when compared to the caddocks. Cymbals also seem to have more texture and extension than with the caddocks. I kept the 1m resistors as caddocks.
I've read some people recommending the FC and NHG panasonic caps, they are cheap enough that I will order some and try them out. The blackgate Ns have become unobtanium and the few I've seen from trusted sources (trusted to me) seem to run abut $50 each. I think I will be skipping these...
All of this is in my system with my ears, the mileage of others will of course vary.
I will post photos when I paint the aluminum perforated cover.
Thanks again for all the support, my system has never sounded better than what it is sounding today!
I've also been playing with the three 100uf caps. I've tried so far Slimic IIs, KZs, Cerafines (older and newer) and STD blackgates. I burned each for about 24 hours (some say not enough for the blackgates) and so far I like the Slimics the best. Compared to all the other caps they sound more defined and increased a bit the width/depth of the sound stage. They also strike a good balance between adding a tad more definition and brightness to the sound. I found the Cerafines were the least bright sounding of the lot, but their sound stage was not as well presented as the blackgates and Slimics. Compared to the Slimics, the blackgates sounded a tad brighter. The originally installed KZs I would rank as last in this pack for me.
All the caps were 24-63v except the blackgates, which I could only find 160v ones for a reasonable price.
Another change for me was to replace the 220k caddock resistors for naked foils (which I was able to afford after taking a second mortgage on my house...). I had already replaced the 220Rs with naked foils. This change opened up the sound when compared to the caddocks. Cymbals also seem to have more texture and extension than with the caddocks. I kept the 1m resistors as caddocks.
I've read some people recommending the FC and NHG panasonic caps, they are cheap enough that I will order some and try them out. The blackgate Ns have become unobtanium and the few I've seen from trusted sources (trusted to me) seem to run abut $50 each. I think I will be skipping these...
All of this is in my system with my ears, the mileage of others will of course vary.
I will post photos when I paint the aluminum perforated cover.
Thanks again for all the support, my system has never sounded better than what it is sounding today!
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If you liked best Silmics you'll have problem with FCs and others low-esr...to my ears they're always a bit harsh.
BTW after 40 hours the Silmics will be brighter than BGs
If available Black Gates (FK better), otherwise (but not final, still investigating) Cerafines.