Group buy/Interest list - TDA1541A Core board.

[wlowes]

Ryanj,

As far as Iunderstand the signal is tapped off a single winding, so the load to the output(dac) never changes, just the signal level to the next stage is changed, makes the load consistent and therefore more linear.
I may be wrong, just how I understand it, as you can see, there are a couple of wires to hook up.......

Laters,

Drew.

Look around in his message board to find the scope of the signal. 5hz to 400hz. Nearly perfect square waves at normal listening levels. As you attenuate the signal you are not resisting it, simply lowering the voltage and increasing the current without signal damage. Arthur Salvatore basically named this approach as the best at any price for a linestage. I have come to the conclusion that any resistor in the audio chain is a bad resistor. You can hear them all and you either perfect them or better eliminate them. The lightspeed is the best if you must have a resistive element. Possibly a switched resistor VC if you use Rhopoint resistors at $30 ea.

 

[AudioLapDance]

My implementation

Looks like you're dating a redhead!

😉

 

[Eldam]

looks like to be expensive traffod reading the link given by Wolwes !

where is connected this device and traffos : between what ?

 

[ryanj]

Hi Guys,
Finally got around to stuffing my Distinction-1541 PCB a few days ago. (was using prototype)
Was just waiting on these to arrive-
VISHAY BEYSCHLAG - RES, MELF, 6K8, 1%, 250MW, SMD
A bit tricky to solder with the chip and caps already soldered.
I think you can spend a bit more and get .1%, but i don't think absolute value is as important as temperature coefficient. I might take a scope shot and see if there is any less noise on the analog outputs. And of course have a good listening session...

Cheers

 

[Eldam]

Hi Ryan,

The best choice possible 🙂 , certainly better than the classic smd thin film !

Where are they sourcable please ? Till easy to source or discontinued ?

 

[ryanj]

Hi Damien,

Element14 has them, very impressive service, i ordered them wednesday night and got them this morning (Friday).

They should be easy to get.

 

[Eldam]

If they could transport me to OZ I would give you some other cap than the FP😛

 

[wlowes]

looks like to be expensive traffod reading the link given by Wolwes !

where is connected this device and traffos : between what ?

It is an Autoformer Volume Control (AVC). It replaces linestages and preamplifiers costing $10k and out performs iff your system is compatible with passive linestage. This is one reason why I use a triode output stage on Distinction feeding short interconnects to a Triode input stage monobloc. Great sound. Tiny ($250) dollars. Works for me.

 

[wlowes]

Hi Guys,
Finally got around to stuffing my Distinction-1541 PCB a few days ago. (was using prototype)
........And of course have a good listening session...

Cheers

Ryanj
Looks great!

I thought about using these R as well but went with some pretty respectable thin film. I can imagine they wanted to escape soldering!

Give it a few hrs to settle in. (I leave mine playing 7/24). Then let us know how it sounds. What did you use for decoupling caps and DEM cap?
Walter

 

[ryanj]

Hi Walter,

Thanks.

Yeah I've got a few new caps and resistors in there, I should go put it on and leave it on for a while- give it all time to settle in.

Yeah it certainly wanted to roll around a bit... good lighting, pointy tweezers and a pointed soldering tip did the trick.

The filter caps are 1uF film, and i managed to fit 2uF (2 x 1uF) on the MSBs - One on top of the other. Im keen on experimenting with a low DEM speed, so this should cover me for as low as 60kHz. Not sure ill go that low though, 100k sounds like a good number.

DEM cap at the moment is just a ceramic 470pF i had lying around (1206 size) Ive got some decent panasonic film caps coming soon - a few different values. (260pF - 1nF, 805 package)

Now that i've got a half decent CRO, i'll take a few shots of noise on the output using different value caps on the DEM. All fun and games!

 

[ryanj]

If they could transport me to OZ I would give you some other cap than the FP😛

You're always hating on my nichicon FPs! 😛 haha.

Ive got some Panasonic SEPC coming soon to try. Element14 didn't have SEP, they look pretty similar, from your experience you liked the SEP version better, yes?

 

[Eldam]

Yes, find the sepc/f dryer : some like it, for me I never had a natural tonal balance with them : they get the things worse and I prefer the SEP most of the time which give a total different result : clear but soft with no lacke of bass! I don't think this due to a higher ESR with the SEP... but don't care to understand : each pcb layout needs its own try & error to find the best. In some environment a sepc could be better, for me most of the time it isn't ! And I'm horryfied when I saw some putting SEPC around a TDA1541 ! You have to try a higher esr with some black Gate or OSCON old SEP to understand what I mean !

I defintly believe my speaker are good as I have a very soft result in the highs with both transcient & clearness... so I don't believe the difference I find between caps is due to the speakers nore the electronyc devices before which are soft : a SMP 1000B from Chord (maybe the only one Chord which is soft and natural while having this speed and energy/speed in bass) , a clinic detailed Yamaha Pre cx-2 but soft (copper wires : Oyaide for modulation, Cardas for speakers... people with experience who listen my hifi said it's like Magnepan but with great bass and diabolic mid-bass and more thickness while not lacke of details; my speakers are Boston Lynnfield 400 L; medium is 125 hz to 2600 hz... I can hear when Miles Davis is scratching him trumpett with the teeths 🙂... soundstage is huge... and very deep with the AYA2 2014... so I can imagine with tubes 🙂 )

I use some copper pipes in the via holes to avoid soldering during tests ! But with the low diameter of the via holes of the Distinction, pipes are not needed !

According to me the FP, have a soft signature in the highs & medium but a flabby bass : dull... like a race of snails on an iranian carpet ! The snails will never pass the line, drying slowly before....
But I never said it can give a bad result in your particular environment : this is not the cap which sounds alone 🙂 (paraboll).

You know my list if no BG at home !I writted here and elswhere often ! It's cheap, you should not private yourself to try and win this few % of improvement !

If loving those Nichicon FP, please try the SE serie : much much better though a lacke also of bass (achtung : 6.3 V max with the SE polymer serie : choose the 470 uF)

 

[ryanj]

Yes, find the sepc/f dryer : some like it, for me I never had a natural tonal balance with them : they get the things worse and I prefer the SEP most of the time which give a total different result : clear but soft with no lacke of bass! I don't think this due to a higher ESR with the SEP... but don't care to understand : each pcb layout needs its own try & error to find the best. In some environment a sepc could be better, for me most of the time it isn't ! And I'm horryfied when I saw some putting SEPC around a TDA1541 ! You have to try a higher esr with some black Gate or OSCON old SEP to understand what I mean !

I defintly believe my speaker are good as I have a very soft result in the highs with both transcient & clearness... so I don't believe the difference I find between caps is due to the speakers nore the electronyc devices before which are soft : a SMP 1000B from Chord (maybe the only one Chord which is soft and natural while having this speed and energy/speed in bass) , a clinic detailed Yamaha Pre cx-2 but soft (copper wires : Oyaide for modulation, Cardas for speakers... people with experience who listen my hifi said it's like Magnepan but with great bass and diabolic mid-bass and more thickness while not lacke of details; my speakers are Boston Lynnfield 400 L; medium is 125 hz to 2600 hz... I can hear when Miles Davis is scratching him trumpett with the teeths 🙂... soundstage is huge... and very deep with the AYA2 2014... so I can imagine with tubes 🙂 )

I use some copper pipes in the via holes to avoid soldering during tests ! But with the low diameter of the via holes of the Distinction, pipes are not needed !

According to me the FP, have a soft signature in the highs & medium but a flabby bass : dull... like a race of snails on an iranian carpet ! The snails will never pass the line, drying slowly before....
But I never said it can give a bad result in your particular environment : this is not the cap which sounds alone 🙂 (paraboll).

You know my list if no BG at home !I writted here and elswhere often ! It's cheap, you should not private yourself to try and win this few % of improvement !

If loving those Nichicon FP, please try the SE serie : much much better though a lacke also of bass (achtung : 6.3 V max with the SE polymer serie : choose the 470 uF)

Thanks for the tips, ill have a bit more of a play around.

 

[ryanj]

BCK noise scope shots.

Just wanted to share a couple of shots i took tonight.

BCK is shown on the bottom trace in all pictures.

1541 PSU BCK noise BWL.jpg
-Noise on -15V supply to 1541A Bandwidth limited (20Mhz).

1541 PSU BCK noise.JPG
-Noise on -15V supply

11025 F5 BCK.JPG
-Square wave 11025Hz -90dB @F5 power amp with -1.5dB attenuation. Bandwidth limited.

Seems BCK shows up nearly everywhere. Maybe its doing more damage than I thought. I wonder how much deterministic jitter its really causing in the chip. 😕

 

[Eldam]

What is the origin according your best bet : -15 V supply ?
I don't remember you conf about regs ?

 

[ryanj]

What is the origin according your best bet : -15 V supply ?
I don't remember you conf about regs ?

Hi Damien,

Looks like BCK is polluting every power supply, its the same story for -5 and +5.

I'm using Salas shunt regs on all supplies.

 

[Eldam]

What could be done ? John's inputs ? : reduce the BCK input voltage from 3v to 0.7 v à la John as the noise is not due to the local decoupling of the three voltage rails but comes from an I2S rail ? Maybe some oscillations due to a smt low value // decoupling at the pins voltage (0.1 uF ceramic ?)

Because if it comes from the dac chip, everybody lives with it from Pedja to Thorsten, or John...

 

[esgigt]

so, I understand, the 1541 is best operated without BCK 😕

@Ryanj : You mention every PS rail to be poluted by bck. Does that also include the pins for the 14 decouple caps?

And how to fix? I guess the use of very low ESR caps might be helpfull...

 

[Luke]

Is it present in the audio out?

 

[sumotan]

Wonder if any of you guys remembered an article by Guido Tent way back about the effects of power supply & damping I2S line.
From my experience low impedance is not the solution for the Tda chip