advertisement


Got Fleas?

Martin,

The DAC is Crystal CS4390. It is fed from the DSP, Sony CXD2508Q. The Sony DSP gets the clock output (original was a JC08 in a metal can the same as the Tent clock). So there is no clock feed direct to the DAC AFAICT.

I'm currently using a Kwak Clock V4 which runs with a 47R on the output, so I'll try the Flea with 33R to start with.

Thanks for your offer of help...don't worry at the moment - I'll shout if i get stuck later.

Jo
 
Finished the Flea, fitted and fired it up....noisy mech, disc stuttering BUGGER.

Removed the 33R from the Flea and replaced it with the 47R from the old Kwak clock output...SUCCESS! Seems this Sony chipset is very sensitive to clock signal level.

I'll leave it running on repeat overnight and go for first listen tomorrow.
 
Nice one Jo, yes that does seem sensitive, Ive had mine spin when theres no clock of course (ie no power) ;)

Leaving on all night ... well yes mine does seem to be changing and I hate saying that!
 
Hi all,
I wish to connect my pfm clock to a marantz 63kisig, I will be using a snaps to power it. I know where it goes, but not sure what conponents to remove ?
I 've read the marantz section on the acoustica site, but not smart enough to comprehend.
Do i still put 0.1uf cap across pins 2+27?
use 5 0.1uf ceramic caps across dac?
(recommends swapping rd01 for a small axial choke and a couple of ferrite beads and increase cd04) what values are ok to use?
Well done to all that made this project possible, can't wait to get mine up and running.
 
In the CD63 (referring to the diagram on the page you mention), you want to remove CD02, CD03, the crystal XD01 and the link. Feed teh new signal into pin28 using the hole vacated by removing the short link, and connect the clock signal 0v to the earth plan adjacent (scrape a small area bare and solder to this).

Adding a small cap across pins 2 and 27 is probably still a good idea. Don't worry about the choke or other caps for now; do one change at a time, then its easier to trace for problems - though I hope you have none!
 
trancera said:
I tell you what, send the superclock to one of the resident guru's for them to do a comparison ;) (if there up for it, perhaps not as the world might not like the answer)
Click to expand...

Actually, I think ALW already has a superclock 2, and he also qualifies as guru, too. If you look at the previous thread, he put forth some useful modifications for the superclock 2 board. He also posted some measurements of the modded superclock that might be usefully compared to the measurements of the flea.

However, the audiocom clock "package" includes/d a second unit: the audiocom superclock 2 PSU, which also uses/d AD797, incidentally. Given this superficial similarity, it would be interesting to know where lie the comparative advantages and disadvantages of the flea and the superclock 2 PSU. From its documentation, the flea certainly looks like a miracle of audio minimalism by comparison.
 
Well guys the flea certainly does improve after a bit of running in for sure and its not a small difference IMHO!
I will admit I wasn't too convinced at first when I put it in my modified Arcam, the detail,bass and top improved but the mids sounded hollow.
I decided to leave it running all last night and for most of today, I just listened to it again now after getting home from work:eek:
The sound has improved dramatically!
To Andy,Martin and anybody else involved, Well done guys! you've done an excellent job with this project;)

My advice to everybody using the flea is please give it some time to bed in before judging it, even if you don't normally believe in burning in, I'd honestly be amazed at anybody who can't hear the difference with these units
 
Myself and Ron have been Pm'ing a little about this (as we both have arcam 5s) and what he is saying is spot on in my experience!

I mentioned in a couple of posts last night that the flea seemed to be warming up, its hard not to go into superlatives. At first I thought a slight loss of bass but its not that at all, the treble has improved dramatically (possibly because NON OS players enjoy a great clock, not sure), someone has changed the drummer on my cd's cos they are hitting snares twice as hard as before.

If I could get this kind of gain for each £50 I spend (say 3 more times) I dont know what kind of system would better this sound. Im sure however that I wont and that this £50 will be the best £50 ever spent on audio.

I want to thank Andy, Martin and the young Jedi Carl (his sabre never stops glowing ;))and anyone else that has contributed to this project (and so quickly delivered) very much indeed, now wheres my iron I got some new caps tonight :D
 
Its sounding really good now:D

You've got more fun to look forward to Trancera;) let us know how you get on with the caps and bits
If you have have op-amp sockets in your A5 try using the OPA627 for the I/V and the OP27's for the output, it sounds quite a bit different to having the OP27 for I/V and the OPA627 on the output:) don't know if it will match your other mods but I'd be interested to hear what you think
 
Hi all,

Just thought I'd post a couple of pics of my build.

I followed Martins advice and swapped the 7812 for a 7808 to enable it to run off 12V input. I also took the liberty of using a 100mA version (it is a flea afterall!) in TO92 package so it would fit comfortably in the can I was originally using for the Superclock.

naked flea:
http://i48.photobucket.com/albums/f215/stucjphoto/DSC00535.jpg

canned flea:
http://i48.photobucket.com/albums/f215/stucjphoto/DSC00537.jpg

Now, when I checked the input my so-called 12V was ony 11.1V, but the LED lights OK and I get 4.9 V at the XO (measured 7.9V at the opamp supply) so to be honest I'm not sure it's working optimally... maybe I should look into upping the supply?

Anyway, its powered up and working and making music.... first impressions... seems detailed, especially in the treble, vocals seem very transparent and have good airiness, but possibly less 3 dimensionality in the bass... I'll keep you posted on what a couple of days burning in brings.
 
Nice job; what are the tiny threaded connectors on the right - SMA?

Now, when I checked the input my so-called 12V was ony 11.1V, but the LED lights OK and I get 4.9 V at the XO (measured 7.9V at the opamp supply) so to be honest I'm not sure it's working optimally...
Click to expand...
that 8v out should be 10V (from 8+2v of the LED) - that 11.1v input isn't giving enough overhead to let the 7808 regulate at all. This means the clock supply is relying entirely on the AD797s PSRR. Since that's 130dB(!) at low frequencies you probably won't notice /would be hard-pressed to measure a difference, but it's not as intended.

Do let it run for a few days though, a different supply is something you can easily revisit later.
 
First chance of a serious listen late last night. This is definitely a clear step forward on my CD player. The initial impression was of a slightly lighter bass, but after 24 hours burn-in, last night all was back in balance.

The overall impression is now of greater clarity across the spectrum...I'm hearing words in backing vocals that were previously masked by the lead singer; better rythmic coherence, less bass overhang.

A very worthwhile result...and I'm looking forward to adding a completely seperate psu to the Flea.

Thanks to the team for putting this one together and to Tony L for hosting the project. A feather in the cap for PFM!

jo
 
The flea is built and burning in nicely before insertion into my CDP, the voltages all check out with those reported, which is always good. After I dropped the Tent clock in the output voltage OP1 read to 2.1V and the flea emitted a loud hummmmmm through the HiFi, via the mains. [Edit] The hum is only there when the positive lead of my DMM is in contact with the output.[Edit]. I was powering the flea with a variable bench supply.

Next step is to build a small PSU, is this transformer a good choice for powering the flea:

http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=696432&N=401

If not can someone recommend a more suitable one? Also, is it OK to just centre tap the outputs, run them into a three pin Schottky rectifier and then straight into the flea via a small cap?

Regards,

Mus
 
Mus, take care, im using a really terrible power supply that is cited a metre and half away from the flea, no twisting it has a figure of eight wire.

Check all is ok !!
 
martin clark said:
Nice job; what are the tiny threaded connectors on the right - SMA?

that 8v out should be 10V (from 8+2v of the LED) - that 11.1v input isn't giving enough overhead to let the 7808 regulate at all. This means the clock supply is relying entirely on the AD797s PSRR. Since that's 130dB(!) at low frequencies you probably won't notice /would be hard-pressed to measure a difference, but it's not as intended.

Do let it run for a few days though, a different supply is something you can easily revisit later.
Click to expand...

Thanks Martin, I guessed something was amiss, I will look into upping the supply shortly...
That said it is surprisingly good at is is, certainly on a par with the superclock - perhaps different rather than better/worse. Not noticed any change yet after 24 hrs...

By the way the threaded connectors are SMB (smaller than SMA), idea was to completely shield the digital nasties - can't tell I do RF for a living :D
 
Thanks martin, for the advice about the marantz 63ki and the snaps, it worked a treat.
The flea is up and running, and it makes the marantz sound much clearer, all round better sound.
Hope you get around to doing a page 4 on the marantz on the acoustica site !
 
trancera said:
Check all is ok !!
Click to expand...

Everything is cool, I didn't explain what caused the hummmmm very well. The hum is only there when the positive lead of my DMM is in contact with the output. All the voltages are spot on and everything is in the right place.

trancera said:
Further to that ive got some 2 x 12 4VA xfrs if you want one? its blue RS encapsulated one.
Click to expand...
Thanks! Do you think they will be OK? If you have a spare one I'd like to give it a try, PM me your email address and we can sort something out.

Regards,

Mus
 
Mus -
The hum is only there when the positive lead of my DMM is in contact with the output. All the voltages are spot on and everything is in the right place.
Click to expand...
Then don't worry about it - the hum is almost certainly some form of pick-up intermodulation . The Tent XO is DC-coupled as far as I can tell on the output, I'm sure adding a DMM as a load when running doesn't help the quality of output ;) I'll try it and see what happens here...
 
about the marantz 63ki and the snaps, it worked a treat. The flea is up and running, and it makes the marantz sound much clearer, all round better sound.
Click to expand...
Very glad to hear it - thanks for the feedback.
Hope you get around to doing a page 4 on the marantz on the acoustica site
Click to expand...
One day perhaps; I've just acquired another 63 to, um , play with...
 
You must log in or register to reply here.


advertisement


Back
Top