[merc]

Way back in March I started talking to Dan about doing a multichannel tubed output mod for a universal player and in August, we decided on the Pioneer 45A as the unit for this possibly "one of a kind" mod. Although doing this mod has proven a bit tougher than Dan expected, I now have this unit in my rack!

I've had it for about a day and a half and although I am not ready to give a final opinion, I must say, I can't stop smiling. Dan, you were absolutely right!

The looks of this unit, although nicely finished, reminds me of the flying guppy series of transport airplanes, seen here:


The totally new and independent analog section of this player sits atop the original unit, which has only been modded in the power section by the addition of bybees(I think). A totally independent power section has been added for the "guppy" analog section. Other mods might have been made for the .1 subwoofer channel, but otherwise, that channel uses the original Pioneer analog tracing. Of course, the other five channels use the "guppy" Modwright addition for their full analog tubed stages.

I also found that I left far too little room above the tubes in my rack for this unit, as I find the heat from five tubes to be warm indeed.

Anyway, this player makes me like my speakers all over again...

More to come including specifics versus other CD and Univ players.... but for now, I'm just gonna listen and enjoy.

Tonight... I'll be using this player via the second set of L/R outputs to do some serious headphone listening...

TO BE CONTINUED....

[merc]

BTW... here are some pics of the finished insides and outside.

http://www.kgjack.com/MCH_Tube_Mod.jpg" width="600">

[merc]

Oh, and BTW, here is a list of the mods as Dan lists them:

1)   Upgrades to power supply – upgrade Harris FRED rectifiers and Black Gates in key locations.
2)   I-V op-amps upgraded to Burr Browns.
3)   Bybee filters (1 pair) installed at B+ secondaries in tube supply.
4)   5CH Tube Analog Stage designed with NOS Tung-Sol 5687 Tubes.
5)   Auricap coupling caps in tube stage.
6)   Ceramic tube sockets and metal film resistors in tube circuits.
7)   Dual transformer tube supply with choke regulation for B+ and heater circuits.
8 )   Shielded Mogami high-grade signal cabling throughout.
9)   Relay controlled power circuit for tube stage.
10)   Separate MCH tube stage enclosure, mechanically isolated with Deflex damping washers between player and tube enclosure.

How does that sound to you all? Musically, that sounds pretty good to me so far...

[merc]

Houston... we have a problem.

Dan,

I turned it on last night and got no sound, and then noticed that the tubes weren't glowing anymore. The unit turns on and operates as usual, but no tube glow and no sound at all.

Today, I pulled the fuse and looked at it and it appears to be perfect. I bought a new fuse and replaced it anyway. Still, no glow and no sound.

Any ideas what I can try next?

I sent you an email late last night and also called and left a message. Please get back to me so we can fix this problem and I can get back to enjoying the wonderful sound.

Thanks!

[Woodsea]

So this unit when it operates will/should work on any 5.1 output player?  This would be awesome!  if it were true.  A real component that could outlast a player.

[Bill Baker]

Hi Merc,
  I have been hearing about this custom pieces for some time now and it's nice to actually see the player.

  I'm sure your current situation will be soon fixed by Dan. He is amoung the best when it comes to standing behind his work. Have no worries there.

  Anyway, I do have one recommendation for your player. I would highly recommend applying an asphalt based damping material throughout the upper chassis and lid to help control vibrations that could enter all those tubes. This made a substancial difference in our RAM CD25 players (same tube stage I beleive) and theres only two tubes in these. You can pick this material up from Partsexpress.com. I don't have the part number in front of me but they have two different types. Use the asphalt, NOT the vinyl base. There is also no odor with this stuff and is about $1.35 a sheet. You will need two sheets total for your unit.

  Running HOT!! I can only imagine. All those 5687s would put off enough heat to heat a small den. I bet it sounds great though!!!

[merc]

So this unit when it operates will/should work on any 5.1 output player? This would be awesome! if it were true. A real component that could outlast a player.

Woodsea,
I don't know enough about this stuff, but since it takes the analog output from the attached player and replaces all the analog circuitry, maybe it could be used with any player?

I'm sure your current situation will be soon fixed by Dan. He is amoung the best when it comes to standing behind his work.

Response Audio,
You are right about that! I communicated both via email and on the phone with Dan and we found the problem. It seems that a diode failed. Dan has recommended that I take the player to a local shop and just have them replace the original diodes with Shottkey 5A diodes, and then send him the bill.

Now... all I need to do is find a good shop in my area and I can get back to enjoying this wonderful player!!!

Thanks for the tip on the damping material. Sounds like a good idea to me.

[modwright]

Thanks John.  To clarify a couple of points.

Your unit does have Bybee filters in the B+ supplies to the tube section.

The stock power supplies have been upgraded with increased filtering, FRED rectifiers and Black Gate caps in key locations.

The stock analog stages have been replaced, with the exception of the subwoofer channel - non-tube.  The signal is taken right after the DACs for all channels - less sub-out - and fed directily (Direct-coupled) to the tube stage.  The output from the tube stage is then fed back to the player and output via the stock output RCA's.

The rest of the stock player received the standard Universal Truth mods, including upgraded I-V stage op-amps and improvements to analog and digital decoupling circuits.

The only caps in the signal path, are at the outputs from the tube stage, where all Auricaps were used.

Thanks!

Dan