Hi,
Just found your site-looks great,
I'm a bit of a digital virgin, but I've had great success moding my TDA1451A equipped player. It's got a SRPP ECC88 output stage with battery negative grid bias, a first order passive filter and some PSU upgrades and sounds miles better than standard.
I'm now looking to the next upgrade and wondered if anyone could advise me on the feasibility of bypassing the digital filter in the SAA7220.
Obviously I'd need to do something about the clock but what else?
Any wise thoughts would be appreciated.
Simon:
Just found your site-looks great,
I'm a bit of a digital virgin, but I've had great success moding my TDA1451A equipped player. It's got a SRPP ECC88 output stage with battery negative grid bias, a first order passive filter and some PSU upgrades and sounds miles better than standard.
I'm now looking to the next upgrade and wondered if anyone could advise me on the feasibility of bypassing the digital filter in the SAA7220.
Obviously I'd need to do something about the clock but what else?
Any wise thoughts would be appreciated.
Simon:
Hi Simon,
Everything you need to bypase SAA7220 digital filter and put your cd player in nonoversampling filterlees mode of operation is here: www.xoomer.virgilio.it/hi_fi/com.htm
- if you have SAA7210 or SAA7310 in DIL, connect pin 23 (SAA7220) to pin 11 (SAA7210/SAA7310)
- if you have SAA7310 in QFP, connect pin 23 (SAA7220) to pin 18 (SAA7310)
This will restore mute function.
Everything you need to bypase SAA7220 digital filter and put your cd player in nonoversampling filterlees mode of operation is here: www.xoomer.virgilio.it/hi_fi/com.htm
- if you have SAA7210 or SAA7310 in DIL, connect pin 23 (SAA7220) to pin 11 (SAA7210/SAA7310)
- if you have SAA7310 in QFP, connect pin 23 (SAA7220) to pin 18 (SAA7310)
This will restore mute function.
Re: Re: Transport screws
When the CD player was supplied new - it would have had two transit screws fitted underneath. They are screwed through two threaded holes in the bottom plate and make contact with the top plate of the CDM. They prevent the CDM from moving around too much on its suspension during transit.
Before use, these two screws are removed and should be stored in the storeage holes on the back plate. When you plan to transport the machine again, you should then re-insert these screws into the threaded holes in the base plate.
It is always better to use the transit screws if available - however, if they are misplaced, it should be okay to transport the machine without them if reasonable care is taken. I have received about 20 CD players with CDM2 and CDM4 in the post - without transit screws fitted - and all of them survived the journey.
Below is a picture of the rear of a Delta 70.2 with the transit screws in the storeage holes just above the RCA outputs on the right hand side. They look just like two knurled knobs. If they are there......unscrew them and find the appropriate holes for them underneath. They should be directly below the CDM.
FibCouple said:
When the CD player was supplied new - it would have had two transit screws fitted underneath. They are screwed through two threaded holes in the bottom plate and make contact with the top plate of the CDM. They prevent the CDM from moving around too much on its suspension during transit.
Before use, these two screws are removed and should be stored in the storeage holes on the back plate. When you plan to transport the machine again, you should then re-insert these screws into the threaded holes in the base plate.
It is always better to use the transit screws if available - however, if they are misplaced, it should be okay to transport the machine without them if reasonable care is taken. I have received about 20 CD players with CDM2 and CDM4 in the post - without transit screws fitted - and all of them survived the journey.
Below is a picture of the rear of a Delta 70.2 with the transit screws in the storeage holes just above the RCA outputs on the right hand side. They look just like two knurled knobs. If they are there......unscrew them and find the appropriate holes for them underneath. They should be directly below the CDM.
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Hi Fib
Great news!
Let us know when you get it and what you think of it.
As Jean-Paul said in the other thread, it is not a machine to rush into with a load of ad-hoc mods. It has been designed pretty well to start with so it needs careful consideration. Also, be careful with the case. It scratches easily and the screw holes strip easily too.
The one mod that is an absolute must even if you don't install a new clock - is to disable the SPDIF signal from going through the 74HC74 shared with reclocking of the bitclock. Apparently this alone can have a huge improvement and is the only real flaw in the design.
Great news!
Let us know when you get it and what you think of it.
As Jean-Paul said in the other thread, it is not a machine to rush into with a load of ad-hoc mods. It has been designed pretty well to start with so it needs careful consideration. Also, be careful with the case. It scratches easily and the screw holes strip easily too.
The one mod that is an absolute must even if you don't install a new clock - is to disable the SPDIF signal from going through the 74HC74 shared with reclocking of the bitclock. Apparently this alone can have a huge improvement and is the only real flaw in the design.
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