opa211 is a single op amp - couple be used in pairs on adapters.
opa2211 is the dual version of this opamp.
Some people dont like blind opamp rolling and I'm sure there are technical arguments why you shouldn't however, I've a big fan of opamp rolling, that way you can test using your ears not a meter!! lol
I'd give it a go. It would need to be bloody good to beat the LME49720HA!
opa2211 is the dual version of this opamp.
Some people dont like blind opamp rolling and I'm sure there are technical arguments why you shouldn't however, I've a big fan of opamp rolling, that way you can test using your ears not a meter!! lol
I'd give it a go. It would need to be bloody good to beat the LME49720HA!
That's poss a bit harsh!!!!!
They are audio grade caps so they will be ok. Having bent here and got the t shirt with cheaper caps, I'd go za on analogue and def no question about sepc on digital. I suspect the sound will be mushier with the stargets!
Hmm - I think I made a big mistake. I removed my DC coupling caps and thought I had tested for offset properly, but did it while the player was paused, not playing. I wasn't happy with the sound after removing them, but kept them out on the understanding that the sound would improve as I did more work on it. Anyway, long story short, I have ~60mV offset in the left channel, ~-20mV in the right, a broken amp and hopefully... hopefully... not burnt out speakers.
It could well have caused the problem 
I would also look at why there is a big difference between the two channels. I generally don't remove the blocking caps if the mV is above 15mV. Remember the amp amplifies that voltage so you could for example be getting 6V on that 60mV channel
Brent
I would also look at why there is a big difference between the two channels. I generally don't remove the blocking caps if the mV is above 15mV. Remember the amp amplifies that voltage so you could for example be getting 6V on that 60mV channel
Brent
I think it's beyond my skill level to figure that out, but it's not so bad because I was actually pretty happy with the sound before I yanked them. I know there's huge untapped potential to be found by ripping stuff out of this player, but I was digging the smooth, vinyl-like sound with all electrolytic caps changed to Black Gates and op-amps changed to LM4562HA. Of course, just 'cos I like it doesn't mean I won't keep changing it, but I'm going to put the FK blocking caps back in and do 1% silver micas next.
Oh hey, while I'm at it - does anyone know what the difference is between LM4562HA and LME49720HA? The datasheets look identical to me...
Oh hey, while I'm at it - does anyone know what the difference is between LM4562HA and LME49720HA? The datasheets look identical to me...
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Great, I can stop playing spot the difference with the spec sheets then.
I was thinking of trying silver/oils as input coupling caps in my amp. If they went in CD63, does one 4.7uF silver/oil per channel sound OK?
There's still a couple of things that don't sit quite right with me about this whole DC offset theory:
- I lifted my 10uF Black Gate AC input coupling caps and they test fine, i.e. they measure open in both directions on all Ohm settings.
- I never heard the slightest pop at any volume level when pausing/unpausing the player.
I might change the battery in my multimeter and burn myself a proper silence track. I want to disprove yesterday's measurements somehow. I'd rather only invest in one pair of silver/oils (for the amp) and I'd ultimately like to be able to wire direct to the output socket on the CD player like the cool kids.
I was thinking of trying silver/oils as input coupling caps in my amp. If they went in CD63, does one 4.7uF silver/oil per channel sound OK?
There's still a couple of things that don't sit quite right with me about this whole DC offset theory:
- I lifted my 10uF Black Gate AC input coupling caps and they test fine, i.e. they measure open in both directions on all Ohm settings.
- I never heard the slightest pop at any volume level when pausing/unpausing the player.
I might change the battery in my multimeter and burn myself a proper silence track. I want to disprove yesterday's measurements somehow. I'd rather only invest in one pair of silver/oils (for the amp) and I'd ultimately like to be able to wire direct to the output socket on the CD player like the cool kids.
Yes but look at the size of them. I use 2.2uF with no problems and they are fitted at the rear of the player due to the size of them.
Brent
2.2uF will be fine indeed for most purposes. This value can be used with a load as low as 10k before the low frequencies start to roll-off. I usually pick them a bit larger though 
.
You can look for a cap with a lower working voltage, they are physically smaller. Like the ones from Auricap or MultiCap, they come in 200V.
There's a '20% off' sale at Partsconnexion...
Regards,
Ray
. You can look for a cap with a lower working voltage, they are physically smaller. Like the ones from Auricap or MultiCap, they come in 200V.
There's a '20% off' sale at Partsconnexion...
Regards,
Ray
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Great timing for a Parts Connexion sale!
I double-checked the terrible DC offset readings and confirmed that the problem went away with the FKs back in. I also replaced the LM4562HA op-amps that I got from eBay with ones sourced from Newark (this time using those cool little BrownDog adapters instead of bending the pins). I'd be interested to test it again now, but I'll probably wait until I have some nice Mundorfs to go in place of the FKs. The poor pcb trace in that area can't take much more swapping in and out.
I was wondering - besides blocking DC coming out to my amp, don't the blocking caps also provide a valuable function in protecting the player from getting DC passed into it? If I was to plug the CD player into equipment with a powered output - e.g. on a PC sound card - would it be likely to get damaged without the blocking caps?
I double-checked the terrible DC offset readings and confirmed that the problem went away with the FKs back in. I also replaced the LM4562HA op-amps that I got from eBay with ones sourced from Newark (this time using those cool little BrownDog adapters instead of bending the pins). I'd be interested to test it again now, but I'll probably wait until I have some nice Mundorfs to go in place of the FKs. The poor pcb trace in that area can't take much more swapping in and out.
I was wondering - besides blocking DC coming out to my amp, don't the blocking caps also provide a valuable function in protecting the player from getting DC passed into it? If I was to plug the CD player into equipment with a powered output - e.g. on a PC sound card - would it be likely to get damaged without the blocking caps?
2.2uF will be fine indeed for most purposes. This value can be used with a load as low as 10k before the low frequencies start to roll-off. I usually pick them a bit larger though
You can look for a cap with a lower working voltage, they are physically smaller. Like the ones from Auricap or MultiCap, they come in 200V.
There's a '20% off' sale at Partsconnexion...
Regards,
Ray
Any Obbligato explosed and no more adivsed?