Tanks, Ricardo.
Now I understand your thought....
I had sensed that the reasons for modify could not be well understood.
The important thing is that you know the reason for this change, then is not mandatory that you make the change or you like it, this is a subjective choice.
Good work.
ciao
Mauro
Hi Mauromauropenasa said:
I am sorry if I caused some misunderstanding.
Just tryed your mod with a 390pF Silver mica and the sound became more clear without the treble "fizz" that sometimes makes voices and guitars to be edgy.
I find your modd very important.
Can I use a 330pF Silver Mica instead of the polystyrenes you indicated ?
Thank you for the very good advise.
Ricardo
Thank you for your test, Ricardo.
I used a 330pF silver mica on my prototype, during the tests.
I think we can also use this type of material, or COG ceramic multilayer...
As shown in the graphs, and also noted Ray, It's better not go beyond 330pF if you do not want to attenuate at 20Khz.
In some cases you can do a value between 220pF and 330pF ...
(Especially if you are using a modified output filter or with not original
shape....)
ciao
Mauro
I used a 330pF silver mica on my prototype, during the tests.
I think we can also use this type of material, or COG ceramic multilayer...
As shown in the graphs, and also noted Ray, It's better not go beyond 330pF if you do not want to attenuate at 20Khz.
In some cases you can do a value between 220pF and 330pF ...
(Especially if you are using a modified output filter or with not original
shape....)
ciao
Mauro
I think that what happens with this new filter is : before there was only music coming out from source. Bi-dimensional
Now, there is'nt a question about HF or Low, or meddle, really, but what appears are musicians with their instruments.Music happens..
IN the past for this mod i did use cog caps. But i think that polistirene 1% are the abosolutely best choice. But, the important is the final effect on sound, no material. There wil be the time.
Now, there is'nt a question about HF or Low, or meddle, really, but what appears are musicians with their instruments.Music happens..
IN the past for this mod i did use cog caps. But i think that polistirene 1% are the abosolutely best choice. But, the important is the final effect on sound, no material. There wil be the time.
Morning guys.
I have 2 questions
I bought some 1N4937 fast recovery diodes for the PSU section and they appear to be able to handle big voltages etc (420v RMS and600v peak reverse voltage). Ray advised recently that Schottky's would be better. Would I find much difference using these as they are so over-specced?
Second
I did the filter mods from Ray's list using the Farnell components specified. My SMD soldering isn't that brilliant, and when I was checking the components for dry joints before powering up I noticed that I measured different values of resistance in the circuit to those before soldering. Have I fried the resistors or am I likely to be seeing the influence of other parts of the circuit?
If I've been ham-fisted with the iron (too much heat) what's the best option? Is there a trick with SMD or should I just use normal sized resistors?
Cheers,
Jim
I have 2 questions
I bought some 1N4937 fast recovery diodes for the PSU section and they appear to be able to handle big voltages etc (420v RMS and600v peak reverse voltage). Ray advised recently that Schottky's would be better. Would I find much difference using these as they are so over-specced?
Second
I did the filter mods from Ray's list using the Farnell components specified. My SMD soldering isn't that brilliant, and when I was checking the components for dry joints before powering up I noticed that I measured different values of resistance in the circuit to those before soldering. Have I fried the resistors or am I likely to be seeing the influence of other parts of the circuit?
If I've been ham-fisted with the iron (too much heat) what's the best option? Is there a trick with SMD or should I just use normal sized resistors?
Cheers,
Jim
Yeah that's what I did. Sorry, didn't make it too clear.
I measured each new resistor once I'd soldered it in and the readings were different to the values out of the circuit, before applying the heat.
Thing is, not all the values were different!
I seem to remember reading somewhere about carbon films changing value if overheated but these are the Vishay metal film 1% jobbies.
Any clues??
I measured each new resistor once I'd soldered it in and the readings were different to the values out of the circuit, before applying the heat.
Thing is, not all the values were different!
I seem to remember reading somewhere about carbon films changing value if overheated but these are the Vishay metal film 1% jobbies.
Any clues??
Hi Brent
This is embarrassing.
When I did the work a couple of weeks ago I'm pretty sure I got a big difference, like 18k became 15k or similar.
Now it's all run in, with the opamps back in and resistors across the opamp pins to bias into Class A, R601....604 read 26.6k which is quite close to the 27k spec, and R607/608 read 17.7k, close to the 18k specified.
Dunno whether it's cos its all settled in or because I've put the opamps back in (I'd taken them out of the sockets for safety!!).
Should have checked before posting!
PS do you have a view on the diode question
This is embarrassing.
When I did the work a couple of weeks ago I'm pretty sure I got a big difference, like 18k became 15k or similar.Now it's all run in, with the opamps back in and resistors across the opamp pins to bias into Class A, R601....604 read 26.6k which is quite close to the 27k spec, and R607/608 read 17.7k, close to the 18k specified.
Dunno whether it's cos its all settled in or because I've put the opamps back in (I'd taken them out of the sockets for safety!!).
Should have checked before posting!
PS do you have a view on the diode question
Improving all the time thanks mate. I've only done the filter, elna RJH's around the DAC, Rayregs on DAC and Decoder, removed DCblocking caps and disabled HDAM's.
I found the same as everyone else. Filter made sound slightly smoother, although that was offset when I changed my OPA2134's for LME49720's. Now they've settled down a bit after 150 hours or so they are much more detailed and revealing.
Regs made a good improvement to dynamics and soundstage, DC blocking caps and HDAM,s revealed much more detail and openness.
Just on with PSU caps, diodes etc, at the mo.
Still haven't got round to the discrete yet, got the Kiwame's but not done pcb's yet.
Missus got me a C1 for Xmas so gonna put that in shortly. Really looking forward to that one!!
Cheers
Jim
I found the same as everyone else. Filter made sound slightly smoother, although that was offset when I changed my OPA2134's for LME49720's. Now they've settled down a bit after 150 hours or so they are much more detailed and revealing.
Regs made a good improvement to dynamics and soundstage, DC blocking caps and HDAM,s revealed much more detail and openness.
Just on with PSU caps, diodes etc, at the mo.
Still haven't got round to the discrete yet, got the Kiwame's but not done pcb's yet.
Missus got me a C1 for Xmas so gonna put that in shortly. Really looking forward to that one!!
Cheers
Jim
