Thank you Simon
I will install my rig tomorrow.... I still wonder where the fumes came from in the sreg ??
Maybe the glue that sticks the transistor under the pcb ??
I will install my rig tomorrow.... I still wonder where the fumes came from in the sreg ??
Maybe the glue that sticks the transistor under the pcb ??
Hi Ricardo
Sounds like the reg is working fine under load.
The FET may have got hot and yes the glue that bonds it to the pcb may have smoked. Those FETs can handle 8Amp on a large sink so would have survived this small error.
Brent
Sounds like the reg is working fine under load.
The FET may have got hot and yes the glue that bonds it to the pcb may have smoked. Those FETs can handle 8Amp on a large sink so would have survived this small error.
Brent
Actually Ricardo the smoke you witnessed may have been some smoke wafting across from Simons cd player. The north of England had a smoke black out for 2 days 😀
Brent
Brent
I have a very nice CD85 in at work for upgrade. It is a proper old school cd player with bullet proof build. I really like the cast chassis.
I have attached a pic of the dac and some of the opamps with a few mods. 14X 220nF PPS caps for dac filter 3 opamps a clock and psu. The difference is massive, I am tempted to get one of these bad boys for myself to mess with. As standard the sound is very nice if a little shut in, now it sings so much more open and detailed with no loss of its musicality.
Oh did I mention the dac is a TDA1541A Single crown
Next job is caps and SPowers on dac and opamp supply.
PICCY
Brent
I have attached a pic of the dac and some of the opamps with a few mods. 14X 220nF PPS caps for dac filter 3 opamps a clock and psu. The difference is massive, I am tempted to get one of these bad boys for myself to mess with. As standard the sound is very nice if a little shut in, now it sings so much more open and detailed with no loss of its musicality.
Oh did I mention the dac is a TDA1541A Single crown
Next job is caps and SPowers on dac and opamp supply.
PICCY
Brent
I heard the CD85 standard (nice but very shut-in) and with C1 (powered from SPower and psu) and some of the PPS caps on the DAC. Spellbinding. There must be something about the 1541 DAC.
Compared to Brent's well-modified CD17KI it's still not amazingly open and detailed and the bass doesn't extend very low, but it has a likeable character and makes you want to listen to the music!
With SPowers and other tweeks I bet it's pure gold.
Simon
Compared to Brent's well-modified CD17KI it's still not amazingly open and detailed and the bass doesn't extend very low, but it has a likeable character and makes you want to listen to the music!
With SPowers and other tweeks I bet it's pure gold.
Simon
Thank you Gentlemen.
Nice CDP you got there Brent.
Must focus now.... Modd time is here.....
Nice CDP you got there Brent.
Must focus now.... Modd time is here.....
Nice job Brent.rowemeister said:
Is the Single crown such a rarity ? I have read about it´s popularity but could never grasp the significance.
Did you glue the psu pcb to the chips... ?
You'll find the single crown in some nice players (like CD85, CD94 and Philips equivalents), and the double crown only in very high end players, the ultimate perhaps being the Marantz CD7.
A single or double-crown simply denotes a better tolerance, probably selected by hand.
Anyway, I don't think a single crown TDA1541 is particularly rare, but that CD85 sounds like some serious sex with only minor mods.... you have to wonder why.
Simon
A single or double-crown simply denotes a better tolerance, probably selected by hand.
Anyway, I don't think a single crown TDA1541 is particularly rare, but that CD85 sounds like some serious sex with only minor mods.... you have to wonder why.
Simon
As the owner of a Revox B-226 S with the single crown TDA1541A 😀
There is something about the sound of this DAC especially when compared to the bitstream dacs as in the CD63/73 (included to keep the post on thread) very musical , IMHO
Andy
There is something about the sound of this DAC especially when compared to the bitstream dacs as in the CD63/73 (included to keep the post on thread) very musical , IMHO
Andy
SimontY said:
Because the chip is uber. I have been interested for a while now to find out how it compares when super-modded.
Lee.
poynton said:
lol, this thread drifts on and off-topic all the time, it's great
I agree about the musical something. I'd describe it as a lack of subjective distortion. The sound isn't harsh or forward, it is refined and laid back and allows the listener to enjoy each instrument in a solid, realistic way, even if detail and other things are somewhat lacking.
Simon
I think the TDA1541A is a lovely chip (although others dislike it - a bit like NOS vs OS, Vinyl vs CD, etc)
I think the crowned DACs are more accurate with their LSB. I'm not entirely certain if the double crown is better, perhaps different (or maybe only marginally better than single crown).
My DAC is alas uncrowned 🙁, but still sounds great. It was really easy to build a TDA1541A based DAC from scratch on stripboard that sounded better than my reasonably modded CD63, so some merit for it.
I think its mainly because its multibit, and maybe because of the silly amount of decoupling going on.
(I did mention CD63 - so it is sort of on thread, not that I ever care with this thread these days)
I think the crowned DACs are more accurate with their LSB. I'm not entirely certain if the double crown is better, perhaps different (or maybe only marginally better than single crown).
My DAC is alas uncrowned 🙁, but still sounds great. It was really easy to build a TDA1541A based DAC from scratch on stripboard that sounded better than my reasonably modded CD63, so some merit for it.
I think its mainly because its multibit, and maybe because of the silly amount of decoupling going on.
(I did mention CD63 - so it is sort of on thread, not that I ever care with this thread these days)
Well i'm impressed with the fluid sound of this dac, very analogue.
Ricardo the pcb is mounted on stand offs with a sticky pad bottom
Brent
Ricardo the pcb is mounted on stand offs with a sticky pad bottom
Brent
Bad Sounds
Hi
I am having very serious trouble after moving the spower near the opamps.
The player stars nicely... then develops some nasty static noises in the left channel... and then stops playing on the left and the woffer starts to come out as if fed by a DC voltage.
on the bench, I seem to have measured +14v on the output left.. but I can not repeat the measurement because it comes and goes.
I just swapped the opamps and the problem persists in the left channel.
What should be the problem here ?
Ricardo
Hi
I am having very serious trouble after moving the spower near the opamps.
The player stars nicely... then develops some nasty static noises in the left channel... and then stops playing on the left and the woffer starts to come out as if fed by a DC voltage.
on the bench, I seem to have measured +14v on the output left.. but I can not repeat the measurement because it comes and goes.
I just swapped the opamps and the problem persists in the left channel.
What should be the problem here ?
Ricardo
Über Sound again
Well.... after cleaning the opamps legs with some Philips 390CCS contact cleaner (an old "friend" of mine for almost 35 years now 😉 ) . the hissing problems disppeared and a melifluous sound was coming out of the speakers..... for a while.... than it came back.
I am very concerned. It seems to me I have bad contact problem in the opamps.... but it is strange to measure +14v on the left ouput... what could cause this exagerated and potentially dangerous offset ??
Regards
Ricardo
Well.... after cleaning the opamps legs with some Philips 390CCS contact cleaner (an old "friend" of mine for almost 35 years now 😉 ) . the hissing problems disppeared and a melifluous sound was coming out of the speakers..... for a while.... than it came back.
I am very concerned. It seems to me I have bad contact problem in the opamps.... but it is strange to measure +14v on the left ouput... what could cause this exagerated and potentially dangerous offset ??
Regards
Ricardo
It sounds like a short between +ve and output, but repair isn't my thing, I'm more into explosions and smoke.
Good luck with it.
Simon
Good luck with it.
Simon
Check the traces to the opamps. If you lose negative supply to the opamp I think it'll output positive voltage, so I'd suspect a simple bad connection/broken track/solder splash type thing.
hmm, I must do some more mods to my player, it's been way too long, (at least a week).
Regards, Lee.
hmm, I must do some more mods to my player, it's been way too long, (at least a week).
Regards, Lee.
Lucky you are Simon....😀SimontY said:
Thank you for the good luck.
Hi LeeThomo said:
That is what I was afraid of ...... tomorrow I will dismantle everything again (ie: remove 4 psu + 4 tx , unscrew the main pcb, remove the white ribbon
bend everything over the big white ribbon connecting to the display...etc..)I will report the damages....
Ricardo