Schematics for the Pioneer PD s507

[hjelm]

Does anyone know if the schematics are available somewhere or if anyone has posted modifications of the player.
The thing i am trying to solve are too much emphasis on the high frequencies and a "uncomfortable" sound.

Anyone who knows if the Silmics that are used as AC coupling filters are any good, for this purpose. Opinions on shorting the AC caps.

[jean-paul]

Leave the Silmics where they are if they are used as coupling caps at the output when they've small values. When a smaller cap can be mounted ( please calculate that with the input impedance of the amp/preamp ) you can replace them for BG N series in super E configuration or a decent film cap that fits.

In case it has NJM 4558 or 4580 I would change them to something good/better. Use the Search or browse the Digital section for advice.

I recall modifying a PDS XXX by placing a new supply for the output stage as it had unregulated +/- 8 V supplies.....

[krishu]

hello,

I ordered the service manual of this player including schematic at www.schaltungsdienst.de and will get it within next week.

There are some commercial tweak kits available for this player, those include the following:

some new diodes (BYV27/200 stuff)
tons of new electrolytics (e.g. Panasonic FC) and some film caps
60 VA torodial transformer for drive unit
OPA2604 OPamps and mica caps for output stage.
X02 clock

Apart from that Bitumen pads and Tyrofoam sheets etc. pp.

When I finished my 507 project i will report.

Cheers
Christian.

[mikes]

In my PD503 I changed NJMxxxx to OP275 /best for me in this case, better then OP2604/, add new electrolyts cap to power supply and I use bitumen spray.

[mrfeedback]

First thing to do is to connect an earth wire to the quartz oscillator can - this helps Pioneer over brightness.

Eric.

[krishu]

Hi folks,

I got my PD-S507 cd player as well as the service manual this weekend. I had to clean the lense quite intensively but now it reads CD-R as well. Unfortunately, It does not accept CD-RW. I know this is normal for cd transports of this age. But is there anything I can do about it?

Apart from that, even in original condition it sounds quite promising.

After I read the schematic I am planning to replace electrolytics as well as diodes to better ones. I will replace the opamp to AD8620. There are a few 1500pF (and 1000pF) caps around the opamp for filtering. Are these ceramic type? What is the best to place there? Styroflex? KP?

Then there are two coupling caps in each analogue stage for blocking DC. I definitely do not want to see them there. May I put them away (put a wire in their place) and measure cd on output?

Considering I have a coupling cap in my power amp, does DC in cdp output matter?

If anybody is seriously interested in the schematics of this cdp he/she may email me. Since I do not know about the copyright i do not want to put it here.

Cheers
Christian.

[mikes]

The ceramics caps are bad for audio...only NP0 types are good /low distortion/. Use NP0 types or polyester types.
And use output buffer /behind the output filter/.
You can measure DC voltage on output without output capacitors, if this voltage will be small no caps is needed.
M.

[hjelm]

Thanks for all replies sofar.
short questions.
mrfeedback: Can i solder on the oscillator can or should i try some form of mechanical connection to the can?

I have also considered using a buffer after the filter since there does not seem to be any?

Is the BUF634 overkill for such an application it is certainly expensive, at least in Sweden.
Another idea is to use a discrete buffer stage from a old hifimagazine in sweden (high fidelity), which was designed by Lars Clausen. Or perhaps peranders diamond buffer.

Just a question does anyone know what happened to tschramas iv stage
here ?

Noone really replied if it was any good or if anyone ever built it?

If i get around to doing anything to the player i will report back.

[mikes]

Output buffer is very useful. If you don´t use BUF use discrete design /something similar to W.Jung buffer/ with OpAmp and apply feedback arround buffer.

I think PD507 have DAC with differential output....in my opinion you cannot use tschramas iv stage exactly...

I designed buffer with discrete uotput stage /better then W.Jung buffer/ . But I haven´t build it yet I´m designig board now.

[mikes]

i´m sorry I saw schematics now and output from DAC is not differential.