savvas said:
...and don't forget to make it spit out I2S rather than EIAJ whilst you are at it. (Player uses TDA1545A DAC.)
Is that happening in the DAC or downstream in the next active stage? Probably would be very amplifier dependent, no?
Martin - I was browsing the Naim CD3.5 bits on your site... did you know you can bypass the internal op-amp of the TDA1305? FILTCR and FILTCL are the inputs to the internal op-amps (for the feedback cap). I'm sure you do know this but couldn't see it mentioned so thought I would.
No. It's happening in the output of the dac, and it's inevitable becasue of the way the maths works.
You can indeed, and it's worth trying if you want to tap the signal off a TDA1305 to try another output stage. Naim's CD2.5 implementation actually uses a f/back cap of a value that differs from the Philips datasheet suggestion though; and the use of this connection is quite critical to Naim's nifty overall 7-pole output stage implementation (i.e. you get a 'zero' in the response if you try your suggestion in a 3.5)
Raygulators: they rocks!
Here is the update of the day, just for the Raygs, as I prefer check if it works before handle the Flea (Guido is alive and my Flea on the road 😉 ).
Also changed my 0.1µF for 0.22µF MKS4. (Shepp is here your pic for pin 4&8 bypass).
Here is the update of the day, just for the Raygs, as I prefer check if it works before handle the Flea (Guido is alive and my Flea on the road 😉 ).
An externally hosted image should be here but it was not working when we last tested it.
Also changed my 0.1µF for 0.22µF MKS4. (Shepp is here your pic for pin 4&8 bypass).
An externally hosted image should be here but it was not working when we last tested it.
Re: Raygulators: they rocks!
Hi Matthieu, that's good news. I hope your XO arrives soon, i'm curious what you think of the sound with the Flea in place. It's still very flattering to have a regulator named after me
BTW, nice clean soldering work on the back of your PCB!
Regards,
Ray
Malefoda said:
Hi Matthieu, that's good news. I hope your XO arrives soon, i'm curious what you think of the sound with the Flea in place. It's still very flattering to have a regulator named after me
BTW, nice clean soldering work on the back of your PCB!
Regards,
Ray
Re: Raygulators: they rocks!
Hi Ray,
What is better for bypass caps (pin 4 to pin 8,op amp): mks,X7R,polystyrene, ceramic disc or others?
Other question: Can I use cheap transformer (non TX) for PSU raygulator?
Tks
Regards
aquar
Malefoda said:
Hi Ray,
What is better for bypass caps (pin 4 to pin 8,op amp): mks,X7R,polystyrene, ceramic disc or others?
Other question: Can I use cheap transformer (non TX) for PSU raygulator?
Tks
Regards
aquar
Hi guys,
I am very glad for this week:
1. I just installed new BG in the DAC,Decoder, Servo and got improvement, especially for center image and dept area.
Sorry for off topics:
2. Chelsea FC still in the champion track (-3 from MU)
3. The true champion for 2nd leg Grand Prix(Sepang circuits) is L Hamilton.....I love with his manuver, very great.
Best Regards
aquar
I am very glad for this week:
1. I just installed new BG in the DAC,Decoder, Servo and got improvement, especially for center image and dept area.
Sorry for off topics:
2. Chelsea FC still in the champion track (-3 from MU)
3. The true champion for 2nd leg Grand Prix(Sepang circuits) is L Hamilton.....I love with his manuver, very great.
Best Regards
aquar
Attachments
Re: Re: Raygulators: they rocks!
Hi Aquar,
I wouldn't use X7R or ceramics (X7R is also ceramic) here for bypassing. Polystyrenes have the best quality, but they don't come in very big values, like 100 or 220n. So that leaves us with the other film caps: MKP (if you can find them in 220n/63V) or PPS (first choice for me) or MKT (MKS is also a film cap). A Black gate N series electrolytic is also a nice solution, and a Panasonic FC has also been tried positively.
For the Raygulators, what do you mean by 'non TX' ?
Regards,
Ray
aquar said:
Hi Aquar,
I wouldn't use X7R or ceramics (X7R is also ceramic) here for bypassing. Polystyrenes have the best quality, but they don't come in very big values, like 100 or 220n. So that leaves us with the other film caps: MKP (if you can find them in 220n/63V) or PPS (first choice for me) or MKT (MKS is also a film cap). A Black gate N series electrolytic is also a nice solution, and a Panasonic FC has also been tried positively.
For the Raygulators, what do you mean by 'non TX' ?
Regards,
Ray
Re: Re: Raygulators: they rocks!
A kind of reward for the work and help provided here!
6h5c said:It's still very flattering to have a regulator named after me
A kind of reward for the work and help provided here!
Thanks for the photo M. Now if I just don't screw up on this...What's the dif. in sound with these things in place...?
Re: Re: Re: Raygulators: they rocks!
Hi Ray,
On hand I have many of 22nF polystyrene and 82nF,100nF,330nF film caps, can I exchange X7R in the ray list mod's with this caps?, very dificult to find X7R in my place.
Here pic of transformer that I mean, what is your opinion if I use diode 1N4007 for rectifier? and I will fit 1000uF/35vx2 BG as main caps.
Regards,
aquar
6h5c said:
Hi Ray,
On hand I have many of 22nF polystyrene and 82nF,100nF,330nF film caps, can I exchange X7R in the ray list mod's with this caps?, very dificult to find X7R in my place.
Here pic of transformer that I mean, what is your opinion if I use diode 1N4007 for rectifier? and I will fit 1000uF/35vx2 BG as main caps.
Regards,
aquar
Attachments
Re: Re: Re: Re: Raygulators: they rocks!
Hi Aquar,
No problem, you can use 100n or 330n film caps instead of the 100n X7R.
That tranny looks o.k. to me, as long as it has the right voltage and current ratings. For the diodes, it's better to use schottkys like 11DQ10 or MBR1100, or 1N5819 if the voltage is not too high.
Regards,
Ray
aquar said:
Hi Aquar,
No problem, you can use 100n or 330n film caps instead of the 100n X7R.
That tranny looks o.k. to me, as long as it has the right voltage and current ratings. For the diodes, it's better to use schottkys like 11DQ10 or MBR1100, or 1N5819 if the voltage is not too high.
Regards,
Ray
Just trying out a TDA1543 non-oversampling DAC in my CD-67SE.
It's just an LM317 adjustable (set to 8.2V), bog standard caps (Nichicon PL on I/P and adjust with polyester bypass, Elna RA-2 on o/p of reg).
The other pot adjusts the bias current which determines the midpoint of the audio (digital silence). This should be the middle of the linear region which is from 1.8V to VDD-1.2V. The I/V resistors are just bog-standard Maplin metal films (2.2K to give 1.8V RMS), and the o/p caps bog-standard Elna RA-2 10uF electros.
The ribbon carries in the I2S from the jumpers just below the player's built-in DAC.
I did it this way so I could try different supply voltages, and change the I/V resistors and bias to suit.
As you can see it should sound crap. Actually, bass is very tight, highs are smooth (and not noticeable dull despite non-OS roll-off) but the imaging is spectacular. Shows promise but this is just a first impression.
I might make another but smaller. Maybe 7808, decoupling across the top of the chip and o/p caps incorporated into output leads.
A popular combo is 8V supply, BG N 4.7uF as o/p cap and Riken as I/V resistors.
It's just an LM317 adjustable (set to 8.2V), bog standard caps (Nichicon PL on I/P and adjust with polyester bypass, Elna RA-2 on o/p of reg).
The other pot adjusts the bias current which determines the midpoint of the audio (digital silence). This should be the middle of the linear region which is from 1.8V to VDD-1.2V. The I/V resistors are just bog-standard Maplin metal films (2.2K to give 1.8V RMS), and the o/p caps bog-standard Elna RA-2 10uF electros.
The ribbon carries in the I2S from the jumpers just below the player's built-in DAC.
I did it this way so I could try different supply voltages, and change the I/V resistors and bias to suit.
As you can see it should sound crap. Actually, bass is very tight, highs are smooth (and not noticeable dull despite non-OS roll-off) but the imaging is spectacular. Shows promise but this is just a first impression.
I might make another but smaller. Maybe 7808, decoupling across the top of the chip and o/p caps incorporated into output leads.
A popular combo is 8V supply, BG N 4.7uF as o/p cap and Riken as I/V resistors.
Attachments
avr300 said:
Yep - same idea. I used an LM317 - mainly because I wanted to play with voltages, and I didn't use the peaking filter to counteract the roll-off (didn't have the parts).
My output circuit is just a 2.2k resistor to ground (gives 2.3mA * 2.2k =5V p-p / 1.8V RMS) and a 10uF cap to the o/p.
The Vref resistor is 500R in series with 1k multi-turn pot to ground so I can go from 500R to 1500R. Varying this varies the DC mid-point or digital silence. That's all it is.
For my 8.2V supply, the linear output range is 1.8V - 7V, so I just adjust the pot so that o/p at silence is half-way between these points (4.4V). So it varies between 1.9V and 6.9V with the 5V signal.
philpoole said:
Tricky one this - I'll not comment definitively until I've given it some more time. Vocals seem to hang in the air, and stuff like Norah Jones does seem to sound much more realistic.
I was getting a very different tonal balance, which was down to the LT1364 op-amps in my 67SE. I was really just trialling these anyway and swapping them for AD825 brought back the mid-bass warmth and sounded more natural than before, narrowing the gap again.
I'm feeding the board from before the 5V regulators (i.e., unregulated digital supply) and I get a bit of hum from servo currents when skipping tracks. Might be better to tap it from the analogue winding.
If I decide to keep it I could relay-switch one set of RCAs between the two dacs, and mount a toggle switch in the headphone socket.... ah, maybe not... but having them both connected to the amp at once causes a hum loop, and I don't have any spare inputs on my amp.
By the way, TDA1543 was £1 from Grandata. 😀
(I got four of the little buggers, came to a fiver including p+p.)
(I got four of the little buggers, came to a fiver including p+p.)