cap choice
Nice one ian oscons in short supply ive used nichicon ls great value from rs @ the mo like the tsups too.😀
C815 will 4700uf zlh 10v be okay saves me ordering again from rs.be nice guys im fragile after my last atempt.
alan
alan
Hi Alan, that's pretty much exactly what I'd use there...in fact if I was ordering right now, I'd probably choose that exact cap!!!! 🙂
Rail is 5v so voltage ok, values good and I like ZLH's!!!!!!!!
Rail is 5v so voltage ok, values good and I like ZLH's!!!!!!!!
my next question would it be worth my while to transplant a 63se tx to a 63 std save me a lot of swapping.
alan
alan
Last edited:
I just discovered this note in the SAA7345GP (decoder chip) datasheet:
1. All supply pins must be connected to the same external power supply.
Whoops...!
1. All supply pins must be connected to the same external power supply.
Whoops...!
Hi Ben,
That's a know issue. This is to make sure all supply voltages come on at the same time at power up. Otherwise strange things can happen... If you use separate PSU's, you should be fine if they are equal in size (power) and buffer capacity, so their start-up time is equal.
Ray
That's a know issue. This is to make sure all supply voltages come on at the same time at power up. Otherwise strange things can happen... If you use separate PSU's, you should be fine if they are equal in size (power) and buffer capacity, so their start-up time is equal.
Ray
Hooray, with a capital Ray!
I'm on 3 separate decoder supplies with no apparent issues. I've been running that way for months. I tried combining them this afternoon as a test and it seemed to make no difference. The supplies are pretty much identical.
I've been having some start-up issues, but I think I've tracked them down to a bad servo clock connection. I have some very broken trace around that area, unfortunately. I've recently had an issue where the sled would sometimes go crazy on a cold start but would be OK if I turned off and on again. I got the board out today and found the servo clock was loose and it seems OK now.
I'm thinking about doing a couple more Fleas for at least DAC analogue supplies.
I'm on 3 separate decoder supplies with no apparent issues. I've been running that way for months. I tried combining them this afternoon as a test and it seemed to make no difference. The supplies are pretty much identical.
I've been having some start-up issues, but I think I've tracked them down to a bad servo clock connection. I have some very broken trace around that area, unfortunately. I've recently had an issue where the sled would sometimes go crazy on a cold start but would be OK if I turned off and on again. I got the board out today and found the servo clock was loose and it seems OK now.
I'm thinking about doing a couple more Fleas for at least DAC analogue supplies.
Last edited:
Short answer is No.
If you want an improvement, use a KI transformer (or multiple transformers)
Andy
.
I did a bit of experimenting recently with my transformers. I went back to the stock KI Tx as a test and was blown away by how much of a step backwards it was. It was unlistenable; just too harsh on the treble. I'd say definitely get yourself a big 50+ VA servo PSU. I currently have the original KI transformer just for my display, so there's loads of room.
😀
Ok, your decoder supplies are fine then. The servo indeed benefits from a large, regulated PSU. You can still use the original transformer to power the peripheral stuff, like the display and microcontroller.
Ray
Ben, do you mount the bigger transformer within the case or externally and if externally how do you do this? Thanks in advance.
Servo PSU
There's definitely some room for individual experimentation with regard to PSU placement, but I find that a 50VA 12V Nuvotem fits in quite nicely behind the CD tray. Wire the secondaries to U308 & U310 and centre tap / both grounds to U309. Tape the original servo secondaries up securely with electrical tape to make sure they don't touch anything or each other.
See this post by Ian for suggestions on how to go further.
Brent also has a good summary of upgrading the servo section on his site here
Ben
There's definitely some room for individual experimentation with regard to PSU placement, but I find that a 50VA 12V Nuvotem fits in quite nicely behind the CD tray. Wire the secondaries to U308 & U310 and centre tap / both grounds to U309. Tape the original servo secondaries up securely with electrical tape to make sure they don't touch anything or each other.
See this post by Ian for suggestions on how to go further.
Brent also has a good summary of upgrading the servo section on his site here
Ben
Last edited:
Sounds spot on to me!!!!!!
A bit off topic, but I treated myself!!!!
Its got 680va transformer, 160,000uF smoothers in the power amp psu and 80,000uF in the preamp. Runs 80+80W full class A fully balanced if you have a balanced source, has a stepped attenuator volume control that runs via 24 relays switching the resistors in and out! I weighs just under 30kgs and best of all its got massive proper analogue VU meters that are lit blue!!! 😱
How does it sound?........er like nothing I've heard previously! I'm actually quite speechless which for me is quite unusual!!!!😉😀
Couldnt resist having a look!!!!!
Last edited:
