opamp replacement & dc offset trouble

[blank527]

Hi,

Thank you for your replies
So then cd enhancer II will be.
Question for Raj1
What power supply did you use for this enhancer?
From the player, or seperate tranny and what kind of filtering?

Regards,
Remco Blankesteijn.

[Raj1]

Hi Remco,

What cd player are you going to use?

You'll have to find out what kind of dac chip it has (current output, voltage output, differential output etc), then use either cd enhancer I, II or III or even sacd enhancer.

I used the cd enhancer II with a pioneer pd-s 703,

I wound my own 4v-4v supply and also around 7v-7v (this is regulated with 317t down to 2.78v)for the heaters of the tubes.

The 4v-4v supply is for the az1 rectifier, this is a lovely tube but it's now hard to get in some places, also the sockets aren't easy to get, I guess it gives it's own mix of sound as it's a dh rectifier....

I picked up a few 120v isolation tranformers very cheap form maplins (only around £5 each) as they've now stopped stocking these so they are reduced, I used one of these for the B+ rail.


Maplins also sell a very cheap but useable 10h choke for around £7.

So my B+ has 2 * 47 ohm res- 4.7uf cap -0.1 uf cap-choke-0.1uf cap-4.7uf cap- 680 ohm resistence-4.7uf cap-40uf cap-4.7uf cap-0.1 uf cap. All polypropylene......


If I were you I'd get someone to wind the tranny for me

100-0-100 @ 100ma
4v-4v @ around 2a
around say 8v-8v @ 0.5 - 1a

Sound is fantastic, better than any cd player I've ever heard. I also removed the 1800 pf silvered mica roll off caps, gave more detail, but the indescribable tube sound remains, kills opamps stone dead (IMHO)....


Thanks
Raja

[blank527]

Hi Raj1,

I'm going also to use an pioneer.
But then the DV-747a wich is an SACD-DVD player.
I've tweaked it also a little bit.
Put lead-bitumen inside it, changed the output caps, removed mute-transistors, more supply capacitance, different decoupling caps, etc. (all worthwile)
This tweak is more effort to take but will be worth it, I hope.
The DAC inside is an CS-4392 with differentail output.
For me the SACD-enhancer will be better because of the less token space.
I'd like to use four or maybe six (sub+center)outputs, wich will take a lot of space when using tubes.
The sacd-enhancer seems a very simple schematic, but still got questions about it, since I don't want to ruine my player.
I see in the scheme that there is no gnd, what happens to the gnd? It is probably connected by the minus of the C-inch connector. (is it?)
The power supply bears me also with questions.
Just use an regular power supply with regulated supply rails?
Anything special to add?

Thank you.
regards,
Remco Blankesteijn.

[Raj1]

Hi,

Best ask ultranalog himself same name as yours (Remco)............

Thanks
Raja

[blank527]

Hi,

I already did
I'll post it when I receive it.
Thanks again!

Regards,
Remco Blankesteijn