[les_garten]

Quote:

Les those are thin copper sheet painted black ( RE1/Phoenix/FBI-500/CD7X ). For the lower end gear I'm not sure what metal is used for the shielding but it could also be CU.
 

Heh, well there ya go, that's what happens when you assume!
 
  Foil "may" help some with RF. Don't think it will do anything for Magnetic shielding.   KW uses a lot of AL as a "shield" where he could probably do  better with steel IMO.  On some of the B22 single chassis threads there was a lot of interesting stuff about how to make those transfos cohabitate with the amp boards, and keep everything quiet.
 
That might be something down your ally, change out the AL between the three main boards with steel as well as the Transfo shields?
 
Might make the inky blackness mo' black.

 

[Pricklely Peete]

The Traffo boxes are steel in the RE1, not sure what they are in the newer stuff. I agree with you Les....aluminum has pretty poor shielding capabilities although I have never had any issues with Kingwa's gear WRT noise floor/EMI/RFI interference (not yet anyway)

 
You could get some adhesive backed copper foil tape (hardware stores should have it if not a decent DIY parts store) and apply it to the dividers surfaces the lid (underside) etc....tie all the panels together to the IEC ground terminal on the chassis back plate. I use the foil in my guitar mods (for the vol pot/pick up wring recess) and it does a great job of quieting Strats (single coils) and of course adds another level of blackness to guitars equipped with humbuckers. The copper tape isn't exactly cheap but it's not expensive either.
 
The B22 thread is full of great info that is for sure...
 
Peete.

 

[les_garten]

 
Quote:

The Traffo boxes are steel in the RE1, not sure what they are in the newer stuff. I agree with you Les....aluminum has pretty poor shielding capabilities although I have never had any issues with Kingwa's gear WRT noise floor/EMI/RFI interference (not yet anyway)

 
You could get some adhesive backed copper foil tape (hardware stores should have it if not a decent DIY parts store) and apply it to the dividers surfaces the lid (underside) etc....tie all the panels together to the IEC ground terminal on the chassis back plate. I use the foil in my guitar mods (for the vol pot/pick up wring recess) and it does a great job of quieting Strats (single coils) and of course adds another level of blackness to guitars equipped with humbuckers. The copper tape isn't exactly cheap but it's not expensive either.
 
The B22 thread is full of great info that is for sure...
 
Peete.

 
 
They're not steel in mine.  After you mentioned it, I broke out the magnet.  No iron anywhere surrounding the Transformers.
 

 

[Pricklely Peete]

Quote:

 
 
 
They're not steel in mine.  After you mentioned it, I broke out the magnet.  No iron anywhere surrounding the Transformers.
 

 
 
Hmm maybe I'm mistaken.....yours are aluminum ?
 
Here's a link to some 3M copper shielding tape from digikey  http://search.digikey.com/scripts/DkSearch/dksus.dll
 
One more http://shop.ebay.ca/i.html?_nkw=copper+shielding+tape&_armrs=1&_dmd=2&_from=&_ipg=
 
Peete.
 

 

[littletree76]

 
Quote:

Littletree76,
 
Are the speakers using an aluminum dome tweeter by any chance ? They might be voiced really brightly. The tube buffer should help just be sure to use decent NOS tubes with it.
 
Peete.

 
You are right, my Mordaunt Short Mezzo1 speakers are constructed with aluminum CPC mid/bass driver and aluminum dome tweeter. But what make the bright sound particularly unbearable is when the sound is reproduced through headphone instead of speaker. Furthermore I play music through headphone only during long work session and fatigue bound to set in.
 
Once I have acquired the tube buffer, the first thing to do is to replace the stock 6N8P tubes with matched pair of Electro-Harmonix 6SN7EH tubes purchased from online store thetubestore.com.
 

 

 

[Currawong]

littletree: What headphones are you using? What cables as well?

 

[les_garten]

 
Quote:

 
 
Hmm maybe I'm mistaken.....yours are aluminum ?
 
Here's a link to some 3M copper shielding tape from digikey  http://search.digikey.com/scripts/DkSearch/dksus.dll
 
One more http://shop.ebay.ca/i.html?_nkw=copper+shielding+tape&_armrs=1&_dmd=2&_from=&_ipg=
 
Peete.
 

Thanx for the linx! I don't know if it's AL, but probably, it's thin and doesn't ring at all.
 
Here's an idea for ya.
 
Replace the dividers between the boards with Iron, and the thin box around the Transfos with steel or if enough room some Iron.  All painted rustoleum black!  Would turn a brick into a heavier brick!
 
I'm actually being serious here...

 

[littletree76]

Quote:

littletree: What headphones are you using? What cables as well?

Currently I am using Denon D5000 in stock condition (stock cable) with rather neutral Purity Audio KICAS headphone amplifier.
 
Note the problem was encountered when the Denon D5000 was connected directly to headphone output of FUN with default DA1852 DAC module. Ever since I switched to DA8740 DAC module, the problem has been resolved. Right now I am thinking of incorporating tube buffer with DAC module reverted back to the default DA1852. Descriptions in my previous posts have not been detail enough thus might have caused confusion.
 
Kingwa has provided following options (listed according to effective level from most to least) to achieve softer/warmer sound signature:
 
1. DA8740 DAC module.
2. OPA-MOON module.
3. Favor jumper setting.

 

[muad]

littletree... I ask everyone the same question. Have you swapped the jumper on the ad1852 module? Try the jumper setting closer to the rear of the module, made all the difference in the world for me.  My next move if I were you would be the moon opa. I found the wolfson dac a little too warm for my taste. Maybe I'll try it again when my new phones come in.

 

[Pricklely Peete]

Quote:

 

Thanx for the linx! I don't know if it's AL, but probably, it's thin and doesn't ring at all.
 
Here's an idea for ya.
 
Replace the dividers between the boards with Iron, and the thin box around the Transfos with steel or if enough room some Iron.  All painted rustoleum black!  Would turn a brick into a heavier brick!
 
I'm actually being serious here...

I'd like to try that but machining the metal dividers and enclosures for the traffos would be pretty difficult and expensive so the next best thing for my situation (limited funds) is to add the copper foil tape (which I'm going to do). Your idea is a good one though. It sure would make the RE1 even heavier than it already is.

 
Quote:

 
 
You are right, my Mordaunt Short Mezzo1 speakers are constructed with aluminum CPC mid/bass driver and aluminum dome tweeter. But what make the bright sound particularly unbearable is when the sound is reproduced through headphone instead of speaker. Furthermore I play music through headphone only during long work session and fatigue bound to set in.
 
Once I have acquired the tube buffer, the first thing to do is to replace the stock 6N8P tubes with matched pair of Electro-Harmonix 6SN7EH tubes purchased from online store thetubestore.com.
 

 

I thought so...those speakers do have a bright voicing as is customary for the designer....the aluminum cones/domes can be troublesome and peaky at certain frequencies. The EH tubes are definitely not worth getting (sorry to say). What you need is a set of NOS RCA or Sylvania 6SN7 GT/GTB. You can get a decent set for 30USD that will outperform the EH tubes by a huge margin. The EH-6SN7 is easily the worst sounding 6SN7 I've ever heard. I have a pair of them (EH 6SN7's) and I got a set of Sylvania 6SN7GTB's right away (for the amp using them), glad I did. Made a huge difference. Use the search function here as there is a really informative 6SN7 thread to glean for some excellent tube choices and their sound signatures.
 
Quote:

littletree... I ask everyone the same question. Have you swapped the jumper on the ad1852 module? Try the jumper setting closer to the rear of the module, made all the difference in the world for me.  My next move if I were you would be the moon opa. I found the wolfson dac a little too warm for my taste. Maybe I'll try it again when my new phones come in.

 
Muad's right littletree76...the 4X setting helps a bit and is very easy to change.......

Here are the pics of the FUN modules as promised muad,
 
DIR9001 Module  ( 2 x 100uf 10V Elna cerafine )
 

 
DIR9001 Module bypass caps ( 2 x 0.1uf 63V Wima)
 

 
Diamond Output module  ( 4 x 100uf 25V Elna cerafine)*
 

 
 
Diamond Output module bypass caps (4 x 1.0uf 63V Wima)*
 
 

 
* just one channel module shown. The R channel board is identical.
 
 
AD1852 DAC module  (4 x 100uf Elna Cerafine 10V)
 

 
AD1852 DAC module bypass caps ( 4 x 1.0 uf 63V Wima)
 

 
 
Sorry about the iffy pics....
 
Peete.

 

[les_garten]

Show off!
 
Yeah, the only thing the REF1 needs is a little IRON in it's diet!

 

[muad]

thanks peete! Any impressions on the sound? Or will that come later?

 

[Currawong]

Littletree: how many hours have you used the fun? It tends to sound quite harsh until you've given it a couple of hundred hours use.

 

[littletree76]

I did aware of jumper setting for oversampling rate (4x or 2x) in DA1852 DAC module as I followed this thread closely before making purchase at end of January 2010. After 300 hours of burn-in (100 hours in factory and 200 hours in my home), I decided to change the jumper position from default location closer toward front panel to achieve 4x oversampling (contrary to what have been posted in this thread). The jumper position was determined by Analog Device AD1852 data sheet and PCB tracing with multimeter. Sibilance (not noise rather excessive "sssssssss" sound in pronunciation) was reduced but high-end still too accentuated/harsh to me through FUN's headphone output and Denon D5000 headphone. Then I tried different favor jump settings in main PCB to no avail and finally replaced the default DA1852 DAC module with DA8740 DAC module. Probably I should have continued burn-in beyond 300 hours before making any change in hardware as FUN requires very long hours of burn-in (at least 500 hours ?). I have taken following route to resolve the issue:
 
Oversampling rate jumper in DA1852 DAC module > Favor jumpers in main PCB > DA8740 DAC module (probably OPA-Moon is a better option ?)
 
I have noticed loss of detail and dynamic range after DAC module switched from DA1852 to DA8740. Thus I would like to have DA1852 in FUN as far as possible. By now the FUN has been in use daily for half a year, it is about time to try again with the DA1852 DAC module and tube buffer. Final configuration for my audio setup as follows:
 
FUN (DA1852 with 4x oversampling, OPA-Earth and DAC output)
> Yaqin SD-CD3 Tube Buffer (6SN7 tubes)
> Purity Audio regular KICAS Headphone Amplifier (not warmer Caliente version)
> Denon D5000 Headphone
 
In case DAC output is worst than preamp output (currently occupied by connections to power amplifier), I will need Y connections to connect both power amplifier and headphone amplifier to the same preamp output of FUN. Further tweaking of sound signature can be done through tube rolling with the tube buffer. Moment of truth will come when the tube buffer arrive next week.

 

[Currawong]

Rather than get a tube buffer, have you thought of getting a couple of OPA627s on a Browdog adaptor and putting them in place of the DAC OPAMP instead?  That will give you your "tube sound" without having to resort to more gear in the sound chain.