Fran, there is a 22K to 47uF RC dropper/filter on the rail towards first stage in Rev1 CCT. Was what we had. Have you got any 4.7u-10u 400V PP to try there? Since the filtering is enough anyway, maybe it can bring a detectable thing or not. I checked my DVM against a dedicated RLC bridge also, and the real value of the 15n 5% nominal caps could very well be 15n+ as yours are 15n3 tested by Vgeorge and seem OK tonally. My DVM shows a bit minus from real.
I should have a cap to suit.... I'll check tomorrow - too much syrah on board right now!
Hey its Friday!
Hey its Friday!
With 22k they still make a good time constant for filtering. If you had say a 4.7 or 10uF SCR would be stronger a filter of course. The main reason for that RC being there is to drop around 30V for correct bias and voltage staggering on the input totem. There is the SSHV and the PSRR of the stage to take care of ripple, so give it a try to see. 350V DC is the lowest you could use.
I added in the mgbo caps today. I wish I had used something more familiar as test before and after - I had a new stan getz album on the deck......
Anyway... Bass seems more snappy and tight - and it was no slouch in that dept before. I think there's also a little more detail in there too.
Now I have to figure out how I'm going to fit the new caps in the case!
I wonder if someone else would try this and report back? It's not a huge change but still audible.
Fran
Anyway... Bass seems more snappy and tight - and it was no slouch in that dept before. I think there's also a little more detail in there too.
Now I have to figure out how I'm going to fit the new caps in the case!
I wonder if someone else would try this and report back? It's not a huge change but still audible.
Fran
Meant to add that the first thing I noticed is that it seemed louder..... Any rational explanation for that? It kinda threw me a bit one of the reasons I'm questioning my ears!
Substituting an electrolytic with something cleaner, if it gave mid bass ''snap'' subjectively can also come across ''louder'' to the ear maybe?
Can you post a recording on Zoom H2 with the MGBO RC rail filter update at a point so we can have an idea too?
Maybe so - there's definitely more snap and the bass is certainly tighter. I reckon there is more resolution too....
Nice. So its either a very good electrolytic to use there or a good quality PP, PIO, etc. 2.2uF-4.7uf, since in ver1 there is high enough R element (22k) anyway.
Sorry cross posting there....
Heres the cap:
mouser cap
I recorded the same bit of music as before (saeta from sketches of spain). unfortunately its a bit louder recording - hard to set recording levels - so you will need to adjust down your volume between tracks, but I think the difference is clear to be heard. File is uploading slooooowwwwlyy to rapidshare.... links shortly.
Fran
Heres the cap:
mouser cap
I recorded the same bit of music as before (saeta from sketches of spain). unfortunately its a bit louder recording - hard to set recording levels - so you will need to adjust down your volume between tracks, but I think the difference is clear to be heard. File is uploading slooooowwwwlyy to rapidshare.... links shortly.
Fran
Good PSU cap, but not low ESR, I have experience with the PS(M) 4700uF 63V 105C ones. Those are half the loss at 120Hz.
Ah crap. I've gone and recorded Miles and sketches of spain, but it shoulda been Van Morrison live at the opera house.
I'll go back and record that, this'll take a little while.....
heres the bit of sketches from tonight...
https://rapidshare.com/files/546288400/new_file.rar
I'll go back and record that, this'll take a little while.....
heres the bit of sketches from tonight...
https://rapidshare.com/files/546288400/new_file.rar
Will listen to that meantime, its not bad you did Spain too, because it was on H1 the other time. Now will be more real on 10kOhm H2 line in.
There is more clarity and detail than in the first one you posted, I can hear the tape hiss now when music is quiet and the trumpet cuts correctly I reckon.
thats the zoom H1 against the zoom H2 with the line in though..... mixed in with the FT-3 teflon caps as bypasses on the output caps and maybe even more....