Paradise Builders

Of course i have connected it. Now i realise the 2MHz has been at the Paradise output all along only it wasn't so clearly visible because of 50Hz and other noises and the scope had trouble syncing.

So, in a way - back to square one, only this time the regulators are rock solid and not adding to the rf chorus.

Caps somewhere? Base stoppers on input transistors? The base stoppers are my least desirable option, first for the lack of particularly nice 16 x 10ohm resistors and second because of the amount of desoldering.

Still curious: are the other 200 builders not experiencing any oscillations? Especially with the inputs shorted? Are my boards cursed?
 
@analog-sa

hi, did you check on different places on the board how the rf-oscillations are distributed? there are two main possibilities: they are generated in the power-supply part or in part of the signal processing chain.

you surely have the 1uf smd decoupling caps mounted (i did not read back through all your posts)?
is the 2mhz signal present on the power rails?

i am shure that a systematic analysis of your board will teach as all a lot ;)
hesener seems to be a great guy, did you consider his offer to send him your board for analysis? i really would be nice to find out where this problem is originating.


a bit off topic: it i funny to see how this resembles my field of work, treating cancer patients.
there every year people rush to congress with wonderful treatment results gained from observations on a small group of patients. then everybody gets interested and things get studied properly on a big number proper way. and - things turn out much less wonderful that anticipated and all those with unrealisticaly high hopes get disapointed.
same pattern i see here, deploying this design to a large community we do find that there are rougher edges than expected. but there is a large amount of expertise gathered here, so i am confident that we end up with a product that may exceed quite a few commercial products in the end. :D
 
Last edited:
you surely have the 1uf smd decoupling caps mounted (i did not read back through all your posts)?



A quick recap for your benefit then. It's excruciating to read through long threads.

Yes, i do have the smd caps, which is probably irrelevant. The mishaps began with the CCS parts of the regulators oscillating @7MHz. It was measured, simulated, cure found and applied and all is now well with the regulators. So, PS is definitely out of this picture.

Hesener was extremely kind to offer his help with the board. At the end it was me who declined his offer. Moreover in less than a month US based forum members will be visiting and i have already promised a phono-stage shootout :)

I also have little doubt that someone in Hesener's immediate vicinity will experience the same symptoms before long. After all there is nothing at all exotic about my build. It uses almost entirely, with the exception of the fets, the components from the group buy which appear to be first rate.

Per example in this post there is an oscillogram, which most probably shows exactly the same problems as the ones i had/have. Scope cannot sync as the power supply is also oscillating.

http://www.diyaudio.com/forums/analogue-source/218625-paradise-builders-17.html#post3312528
 
Battery died after first pic...
 

Attachments

  • reg caps.jpg
    reg caps.jpg
    251.9 KB · Views: 427
Member
Joined 2005
Paid Member
Sadly, that didn't help. Bypassing them when voicing is probably a must, but first it has to work properly.

I do have some ideas how to fix it, but before releasing them I want to verify (as is proper engineering practice). To do this, I need boards that are oscillating, hence a repeat of my offer - ANYBODY out there who has oscillating Paradise R3 boards, ship them to me and I promise a quick turnaround.

I do have a couple boards but havent found the time to look at them yet. I believe they are not oscillating though.....
 
Member
Joined 2009
Paid Member
My boards are powered and sat on a shelf with voltages as posted by Alfred in his replies to quan and pin 6 on one fluctuating around 0.5V and the other 1.5V.Outputs are fluctuating around 200mv.hopefully things will settle after a few days.Would it be better to case them up to aid things in settling?