I need to preview my posts
That is a high pass filter that rolls off the bottom.
The 10 hour drive to Memphis has jellied my brain even more than usual. Caught some smokin' jazz and blues tonight to make it worth it.
George
That is a high pass filter that rolls off the bottom.
The 10 hour drive to Memphis has jellied my brain even more than usual. Caught some smokin' jazz and blues tonight to make it worth it.
George
Nordic said:
Hi Nordic
the .47 will work OK but cut the bass to some extend. the 2.2 will also work and you will have much more bass. not as tight but you might prefer it. but the downside is that the bipolar is a bad choice for good sonics.
I would suggest that you go to Mantech and get the 1uf Wima MKP they are very big 250 or 600 v but VERY GOOD quality. and use them on them after the RCA input. they should have them in stock down in CT
I have tried my system without the CAP but as the others have noted , you should measure if there is any DC comming from your source. I have a pair of 1.5uf Wima MKP10 in my DAC's output so i do not have a DC problem
Rudi
Got my Kits today..
Well after 1 and a half hours I have one board done; not bad considering I had three boys watching and asking 1,000 questions on what I was doing, and what all those pieces of things were, and what is this all for 🙂
Hpe to have things into a case and testing by the end of the weekend.
Nicely put together kit!
Jonathan
Well after 1 and a half hours I have one board done; not bad considering I had three boys watching and asking 1,000 questions on what I was doing, and what all those pieces of things were, and what is this all for 🙂
Hpe to have things into a case and testing by the end of the weekend.
Nicely put together kit!
Jonathan
Changed feedback cap
Hi there ! An hour ago I changed my Panasonic FC feedback caps for Sanyo Oscon 220 µF /10V. The change in sound is dramatical ! First impression is that the highs have an much wider open end, much more clearity in voices. Alison´s voice (Goldfrapp) is soooo sweet ...
Got to listen - bye !
Hi there ! An hour ago I changed my Panasonic FC feedback caps for Sanyo Oscon 220 µF /10V. The change in sound is dramatical ! First impression is that the highs have an much wider open end, much more clearity in voices. Alison´s voice (Goldfrapp) is soooo sweet ...
Got to listen - bye !
I glanced at the schmatics this morning and think something as simple as lowering C29 and raising C27 would involk a simple high pass function on the amp and NOT affect anything IN the actual amp.
As I mentioned previously, the slope and freq. are not THAT big of a concern since the low pass can be adjusted to blend. The drivers are 6.5" mids to 10" woofers so the the mid can go quite low, and the woofer (Aluminum cone) can go up as high as 400 -600 Hz easily.
EDIT:
"I changed my Panasonic FC feedback caps for Sanyo Oscon 220 µF /10V"
I did not see a 220uF in the feedabck path. May I ask the componet number of that cap?
As I mentioned previously, the slope and freq. are not THAT big of a concern since the low pass can be adjusted to blend. The drivers are 6.5" mids to 10" woofers so the the mid can go quite low, and the woofer (Aluminum cone) can go up as high as 400 -600 Hz easily.
EDIT:
"I changed my Panasonic FC feedback caps for Sanyo Oscon 220 µF /10V"
I did not see a 220uF in the feedabck path. May I ask the componet number of that cap?
I think the caps that SmellOfPoo has changed are C9 and C24. The voltage rating of that caps in the original components list is >35V... I'm not sure but I think that 10V could be too low
Mark
Mark
mark_titano said:
I changed C9 (?) only, it´s the elytic closest to the input cap. Before changing it I missed to measure the voltage going through it, but on the levels I listen the amp never puts out more than 3 V (measured with a true rms voltmeter on different freq.) and so I think 10 V are enough.
An externally hosted image should be here but it was not working when we last tested it.
SonOfPoo
You've got the single board version, haven't you? i seem to remember you posting that you split ypur board down the middle.
Thenyou would not have the 100nF 100v Wima Polyester (C21) bypassing the 220uF, as in the Mono boards, Rev_C_2_1a.
There likely would be a lesser benefit with a cap upgrade on the later Mono board.
Audie.
You've got the single board version, haven't you? i seem to remember you posting that you split ypur board down the middle.
Thenyou would not have the 100nF 100v Wima Polyester (C21) bypassing the 220uF, as in the Mono boards, Rev_C_2_1a.
There likely would be a lesser benefit with a cap upgrade on the later Mono board.
Audie.
SmellOfPoo,
Sorry I got your name wrong. It's very late in Aussie.
Just hape your Dad's not upset!
Audie.
Sorry I got your name wrong. It's very late in Aussie.
Just hape your Dad's not upset!
Audie.
So I´didnt mention the Wima MKS4 0,1 µF bypass cap over the Pana cap ? 😉 In fact there was one, I forgot. My boards are the beta version of the monos, so the labeling may differ from the final revision. However, in my ears there is a big improvement with the Sanyos. 
billabong said:
I was just about to get the next plane to Sydney (how to hide my gun from these f***ing metal detectors ?), move straight to northwest and ... 😉
SOP,
Showdown on Main Street!
But with a name like that, I just know you would go easy on an old codger!
Audie.
Showdown on Main Street!
But with a name like that, I just know you would go easy on an old codger!
Audie.
Cerafines look like a low cost upgrade.
I just looked, but Welborne are out of stock on the 220uf 35V, which might fit, as it's 0.5' (D). The Panasonic is 3/8' (D).
Audie.
I just looked, but Welborne are out of stock on the 220uf 35V, which might fit, as it's 0.5' (D). The Panasonic is 3/8' (D).
Audie.
SmellOfPoo said:
I named C9 and C24 because I've used the original Penasa's layout for my_My_ref...
You can see here the original schematic:
http://www.audiofaidate.it/materiale/My_ref_A_SCH.pdf
Even if I've not still tried them, I think that the Rubycon ZA could be another good solution in that position
http://www.farnell.com/datasheets/101.pdf
in this way you'll be able to put in a 220uF/35V that fit the original ratings 😉
Mark
BrianDonegan said:
Brian, I have some 220pF ceramic disc caps in my gainclone. Would they be killing my sound too? Sorry, I am new to all this and was worried about it after reading your post. Is it better not to use ceramic discs in any audio equipment?
Thanks ahead.
In general, it is not good to use ceramics directly in the signal path, as an input capacitor, for example. They are often okay to use in feedback compensation networks and the like, but can introduce a lot of THD when used in the signal path.
Something I learnt recently while building the leach was that not all ceramics are bad for signal path work. NP0 or C0G types have been mentioned to be better than polyprop polystyrene and possibly about the same as silvered mica.
Got new input caps today, could not get WIMA's though, but these look nice enough, Have to wait till Wednesday for the DIY shop to complete cutting the pannels for my case (i'll probably get impatient and test them somewhere before then).
Was going to stick a bunch of these boards into a big box, but was diffirently inspired by the heatsinks I eventualy got... going for miniature layout now.
Was going to stick a bunch of these boards into a big box, but was diffirently inspired by the heatsinks I eventualy got... going for miniature layout now.