rowemeister said:
Hi Brent,
Nice photo's, good job. That reg PCB looks very neat. I was just looking into some regulator data, cause i'll be doing some separate regs too in a while. Still haven't decided on what regs to use.
Isn't the noise for these regulators (LM/LT1084...86, LM317) a typical 0,003% of Vout? That means 150uV at 5V out, while a standard 7805 does 40uV.
Regards,
Ray.
6h5c said:
Off the top of my head im not sure. I used 7805 for my servo reg pcb on my uber player and found the 1084/86 adj gave me better bass and a slightly better bass.
I also have some plastic caps to fit across the caps after the regs.
Brent
Hi all
Hope this isn't a stupid question. I am getting ready to order the brownbog pcb's
for single to dual using OPA627&OPA132. Here is my question do you use 2 opamps pre pcb? Because the OPA2604 are dual opamps the ones that are in there now.
Regards
Dave
Hope this isn't a stupid question. I am getting ready to order the brownbog pcb's
for single to dual using OPA627&OPA132. Here is my question do you use 2 opamps pre pcb? Because the OPA2604 are dual opamps the ones that are in there now.
Regards
Dave
rowemeister said:
Hi Brent,
I'll look into the datasheets a bit more. Noise spec's aren't everything. Maybe output impedance or ripple rejection has something to do with it. But i've heard it before, that low-drop reg's sound better.
I'll keep it in mind 😀.
Regards,
Ray.
Gooch said:
Hi Dave,
There's no such thing as a stupid question, unless you know the answer already 😀.
The two opamps in the player are dual opamps, with two identical opamps in one 8 pin housing. So actually there's four of them. Q605 is used for the left channel, and Q606 for the right. The first half of each chip (pins 1, 2 and 3) is used after the DAC, and the second half (pins 5, 6 and 7) is in the analog filter. With dual opamps you always end up with the same opamp in both places, and that's not optimal. But the adapter enables you to use two different single opamps in a dual socket on the PCB.
To use OPA627 after the DAC and OPA132 in the analog filter, is a nice combination. For each channel you need an OPA627 and an OPA132 (both SMD of course), and a BD adapter. Place the OPA627 in the position of IC1 (on top) of the adapter. Place the OPA132 in the position of IC2 (bottom) of the adapter, that's it. Look at the dot for the pin 1 mark, and make sure you place them the right way around. So each adapter indeed holds two different single opamps.
Regards,
Ray.
Attachments
Hey thanks Ray
I am glad I didn't order the opamps yet I was looking at the opamp chart and it got me thinking so I thought I better make sure that there was two for each channel.
I will post my results when I get them clock card will be here next week also.
I am glad I didn't order the opamps yet I was looking at the opamp chart and it got me thinking so I thought I better make sure that there was two for each channel.
I will post my results when I get them clock card will be here next week also.
Yep, 2x dual = four singles! Ok, keep us updated with the results. Personally I like this combination very much. An external clock will bring a lot of improvement also.
Did you notice you have a smiley in your signature 😀 ?
Ray.
Did you notice you have a smiley in your signature 😀 ?
Ray.
I have some OPA627 on order and im going to try the 4x 627 opamp. Which ever one i prefer the other combo will go into the custom TX KI.
Can't wait to hear the difference.
Brent
Can't wait to hear the difference.
Brent
Hi everyone
I need some help I bypassed the HDAM on Monday and been listening to it all week.Well today someting weird started to happen CD plays to track 3 then stops thing.😕 I tried diffence CD they all do the same thing.
I need some help I bypassed the HDAM on Monday and been listening to it all week.Well today someting weird started to happen CD plays to track 3 then stops thing.😕 I tried diffence CD they all do the same thing.
Gooch said:
Sounds like the flat cable going to the transport, J103
put slight pressure ontop of cable and play something.
allan
Hi Allen
I did that and it didn't help. I wounder if the lazier went out of focus for some reason
Regards
Dave
I did that and it didn't help. I wounder if the lazier went out of focus for some reason
Regards
Dave
Gooch said:
My cdp played for 2 or three tracks then just stopped.
i had meters and scope on everything trying to find why
thought it was my clock upgrade (loosing sink) or the clocks psu but no.
cleaned laser (dry cotton bud)
replug the cable a few times it played for 4 to 5 tracks
I was starting to think of laser problems too
but
tried moving (bending) cable when playing, no success.
finally put a kink in the cable
no more problem😀
allan
ps someone mentioned a cap on the transport pcb that dry's out
and gives similar problem to weak laser.
Yes it could be some crap on the laser assy, usually caused by the grease going hard.
Clean off the grease and it should be ok.
Brent
Clean off the grease and it should be ok.
Brent
Still trying to fix my display again (which broke not for the first time, lol!)
D852 seemed suspicious so I replaced it with a wire jumper, still not working.
I checked the joints around C854, D851, Q851, C852, D852, C853 and all seems fine.
The front panel receives its +5v (problem last time), this time it's the -24vdc. (should be lower, ~-18v now I replaced D852 with wire.)
If anyone would like to suggest what to do I'd be grateful. I didn't want to ask for help again but I'm a bit stuck now.
The 3.6vac between orange and brown wires measure ok.
The -19.5v isn't right. I'm confused and I don't understand this complex psu arrangement.
The problem is around the 7918 regulator (Q851), it measures:
pin1 - 0
pin2 - -36
pin3 - -26
I don't think this is at all correct, lol!
D852 seemed suspicious so I replaced it with a wire jumper, still not working.
I checked the joints around C854, D851, Q851, C852, D852, C853 and all seems fine.
The front panel receives its +5v (problem last time), this time it's the -24vdc. (should be lower, ~-18v now I replaced D852 with wire.)
If anyone would like to suggest what to do I'd be grateful. I didn't want to ask for help again but I'm a bit stuck now.
The 3.6vac between orange and brown wires measure ok.
The -19.5v isn't right. I'm confused and I don't understand this complex psu arrangement.
The problem is around the 7918 regulator (Q851), it measures:
pin1 - 0
pin2 - -36
pin3 - -26
I don't think this is at all correct, lol!