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Old 2nd August 2003, 03:28 PM   #101
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Quote:
Originally posted by mikelm


hi Guido

OK but does it work for TDA1545A as in my CD723 ?

does it matter that, apparently, I will be doubling the frequency of BCK.

where can I get details about your clock cct ?

do you do a cct board for it ?

all my cd psu's are batteries - sounds nice. Would you recommend any additional regulation after the battery for your clock cct ? ( apart from a good quality cap )

cheers

mike

Hi

I do not know the 1545, but you may compare both datasheets. Mail me offline for more info on clocks.

Yes, I recommend additional regulation.

best regards
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Old 30th November 2003, 05:08 PM   #102
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Default CD723 I/V op-amp

I have recently been using two NE5534s as I/V in the CD723 with very good results, but as the NE5534 (without compensation capacitor) is not stable at unity gain can anyone please offer advise regarding the suitability of a non-unity stable opamp for I/V in the CD723 circuit?

Many thanks for any help,
Tim.
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Old 30th November 2003, 05:19 PM   #103
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Default NE5534 again !?!?

OPA627 is unity gain stable and excellent sounding. You can remove the caps that are needed for keeping NE5534 stable at unity gain. Since you really need a dual opamp AD826 or LM6172 might be a better choice.

But maybe I misunderstood you post !?!?
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Old 30th November 2003, 06:24 PM   #104
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Default CD723 op-amp stability

Jean Paul,

Thankyou very much for help.

Are you saying that the NE5534 (that is not stable at unity gain) will be stable in the CD723 as I/V. If so, could you please explain to me why this is so, for example is there enough gain in the circuit to prevent instability with the NE5534, or is op-amp stability for I/V not relevant, if so why?

Yes, I have tried the OPA627 and LM6172 but surprisingly I prefer the sound of the NE5534 (biased into class A) in most respects!

I would like to understand the requirements of the CD723 circuit with regard to op-amp stability. If you have time to explain briefly I would be most grateful.

Many thanks,
Tim.
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Old 30th November 2003, 11:02 PM   #105
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Too late now, maybe tomorrow when time permits. When NE5534 sounds better than OPA627 there must be something wrong in your cdplayer
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Old 1st December 2003, 07:45 AM   #106
mikelm is offline mikelm  England
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Hi Tim,

From your postings here and elsewhere it seems that we similar CD and amps - modified cd723 & a version of JLH simple class A.

I would be interested to compare ideas and perhaps equiptment sometime.

I live in the north but my family are in the south so I come down quite often.

cheers

mike
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Old 4th August 2006, 02:07 AM   #107
weng is offline weng  Philippines
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Default Philips CD721

hi,

my philips cd721 quit playing today. it only shows "NO DISC" when a cd is inserted and thats it.

is this problem repairable? tried good/new cd and still the same problem persist. any tricks to tinker inside to make the cd working again?

thanks
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Old 4th August 2006, 07:24 AM   #108
Nuuk is offline Nuuk  United Kingdom
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Did it just stop working or have you done any mods recently?
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Old 4th August 2006, 09:13 AM   #109
weng is offline weng  Philippines
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hi nuuk,

no mods has been done to this cdp. just quit on me a couple of days ago.
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Old 4th August 2006, 10:38 AM   #110
Nuuk is offline Nuuk  United Kingdom
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Ok, this is a long shot but you may as well try it. Remove the lid and you will see the transport assembly on the left side of the case. Look at the plastic cradle that is screwed to the chassis (usually only by two screws at the rear). Turn these two screws anti-clockwise by half a turn and then try it again.
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