Bizarre issue (Audio Alchemy)


Well...my first post here is unfortunately a "cry" for help. 
I recently purchased an Audio Alchemy DDP-1 DAC/pre amp. I paired it with the PS-5 power supply upgrade.
I am using a Classe' CDP10 player with option to run the transport to the Alchemy DAC or the Classe' DAC to the Alchemy analogue stage.
The rest of my system is a Rega RP6 with an Audio Alchemy phono stage and a Krell KST 100 into Revel M-20 Performa speakers. Interconnects are all Blue Heaven II's save for a PBJ phono to DDP-1 and a Moon Black Dragon digital connect from Classe' out to the Alchemy digital in.
Everything is plugged into a PS Audio Dectet.
I am gradually upgrading everything.

Here's the problem.
The rig runs exceptionally well-- no complaints re: the sound--until after a few hours there is a 'sudden" loud fog horn sound from the speakers. I mean LOUD! Literally blasting. I can find no reference on line to a similar sound. This sound is not impacted by the Alchemy volume control and can be eliminated only by shutting the system down. It does not return upon re-start until an hour or so later.
I suspected the Krell. I replaced the Krell with a pair of powered Audio Engine 2's and after a while same problem returns.
I removed the phone pre-amp using digital source only--and problem remained
I then suspected the power supply for the Audio Alchemy and returned it to the retailer --it was replaced and sure enough after several hours of perfect running the fog horn returned!
I am now planning to contact the retailer and have the DDP-1 replaced. I also will e-mail Peter Madnick at Audio Alchemy.

Thanks to anyone hanging in to this point. I am wondering what the knowledgeable folks out here think.
Any thoughts and advice would be greatly appreciated. 

I have to say--the Audio Alchemy units are terrific. Great sound (especially at the price point). I am somewhat certain the issue is somewhere with one of the three AA units--process of elimination has me down to the DDP-1.
128x128johnlnyc
I agree that you should remove the  PS Audio Dectet from your system.  It is possible the fuse in the unit could be a causing your noise problem.  
Great suggestion! Will try that --plugging the external power supply (PS-5) into wall (hospital grade wall plug). 

Never thought to consider the Dectet as possible source of the problem.

 The problem is a strange one--appears intermittently and after hours of play with no problem at all. Impacts both analog (records) and digital (CD's).

Thanks
Will keep you posted.

hgeifman
see above.
I used the Dectet successfully with old system-- Linn Axis--Classe CDP10-into Conrad Johnson PV10 to the Krell no problems.
(only the Krell into the High Current input). No problems.

So far with PS-5 powering the AA units plugged into the wall (Rega, CD player into the Dectet) seems to be fine--at least now. 




It sounds like the Audio Alchemy DDP-1 DAC/pre amp with the PS-5 power supply upgrade needs to be plugged direct into the wall plug and not connected to the PS Audio Dectet.   Please keep us posted on how this works.   


"Inside the PS-5 are two separate, regulated power supplies: one for analog circuits, the other for digital and control circuits, which provide each the unique power qualities required to maximize their performance. These discrete supplies are routed into the DDP-1 (DAC/Preamp/Headphone Amp) through a special multi-pin connector on the rear of the unit for easy connectivity.

Additionally, the AC-to-DC conversion is performed inside the PS-5 to prevent interference with the sensitive analog audio circuits inside the DDP-1.  A balanced supply with separate analog and digital/control feeds, separate positive and negative rails for analog circuits, and large banks of storage capacitors for better filtering and improved dynamics".

Based on the above technology, my assumption is the Audio Alchemy PS-5 Power Supply needs to be plugged DIRECT into the wall plug and not the PS Audio Dectet.