(RE)Building the Perfect Beast...

[spritzer]

I thought it would be fun to document the insane amount of work it will take to turn the Single Power ES-2 into something useful.     Now Kevin had done quite a bit of work for me such as fitted new teflon tube sockets and teflon Stax sockets but that still leaves a lot of shit to do.  Here is what it looked like when I got it:

 

 

The wooden front for the amp section was cracked so Kevin threw it out.  The weight of just the empty chassis was pushing 24kg so my first decision was to ditch the PSU and do it internally.  First up do the back panel:

 

 

Here is the reason why I don't add RCA's to my amps...

 

 

Now for the front panel.  Mikhail had plenty of very useless holes there for various functions that never worked.  This makes things tricky but the front needs to have four 50K pots to adjust the offset of each output tube, two 5K pots with two test points for each to adjust the front end balance.  One quad pot as well as a rotary power switch to hide some of those extra holes... 

 

 

Now comes the fun part of cramming power supplies into the chassis... 

Edited November 15, 2014 by spritzer

[mikeymad]

Looking forward to it... 

[nopants]

are you building the original amplifier or making circuit changes

[Tyll Hertsens]

There's so much insanity going on here I don't even know where to start....

 

Fortunately, you did.

 

 

:popcorn

[RudeWolf]

Good thing it comes with a paddle!

 

How sound were these SinglePower beasts circuit wise? I was late to the party and all I heard was warnings about them demolishing your house at night with capacitor explosions.

[spritzer]

That paddle will go on my wall.   

 

are you building the original amplifier or making circuit changes

 

The stock amplifier never worked correctly and had a permanent offset of -110V so I'll build the fixed ES-X instead.  For this I need a +/-400V PSU's,  a second -430VDC supply for the output tube bias and then a +12VDC supply for the front end heaters.  I found a good deal on some 12SL7's so it makes sense to use them instead of new production 6SL7's.  The chassis already has four large 50K resistors attached so I'll use them instead of adding a CCS. 

 

There's so much insanity going on here I don't even know where to start....

 

Fortunately, you did.

 

 

:popcorn

 

The crazy shit is half the fun.    Some things in there just didn't make any sense, such as the inputs.  He had XLR's wired as one would but the RCA's were simply connected to the XLR + and nothing done about the - leg.  How that was supposed to work is beyond me... 

[nopants]

With a chassis that big it almost seems like a waste to fit in the ES-X (SR-X)? From the pictures I spot a two-box implementation?

 

That being said I'm always a fan of p2p work so I'm looking forward to the end result. 

 

I'm also in possession of several chassis that have a ton of holes in the face plate (for the dynaFET iirc). I've been looking for a while for something to plug holes intended for chassis-mount XLRs.

[spritzer]

Here is what it looked like new:

 

 

Three umbilicals as Mikhail never used anything but those bloody Speakon connectors.  The screen was a voltmeter which floated and thus didn't work.  I'll probably have the MA logo laser etched into some acrylic and light it from the side. 

 

Ohh and Kevin thought this was funny...

 

 

That used to my IEC chassis punch.  I was only using it to mark the right size for me to cut the IEC but it really didn't like that.  I managed to snap a 1/2" hardened steel bolt and have the bearing implode by hand. 

[Cucera]

Wow, looks good. Maybe you can get at a place where it sounds at least as good (or bad) as a SRM-007t.

Did one of those actually cause a fire?

[spritzer]

It will eat the 007t for dinner when I'm done with it.    This is a far better amp. 

 

Not one of these, no but some of the Singlehour stuff came close. 

[kevin gilmore]

 One of the variants of the "rabbit out of the hat" sketches has Bullwinkle saying, "Don't know my own strength."

 

I already have an es1 I rebuilt, pictures were posted. Mine is a 2 box because the amp box was much

shorter. But really I did not need 2 of these.

 

The SS1 rebuild was it for the monster singlepower disasters.

[DefQon]

Always like the chassis aesthetics of the ES-2. Designing something similar with a two piece faceplate involving alu and nice stained wood for my KGSSHV and balanced B22.

[spritzer]

Almost three years later, I'm finally working on this again.  This is such an epic project as well...it is certifiable.    The front panel is finished and mounted to the top plate. 

So very busy... Power knob on the left, volume on the right.  Four 50K pots in the upper left hand corner to adjust the output stage offset and balance.  Two 5K pots in the lower right hand corner with all the test points.  Those cost a bloody fortune but were the only ones to fit in those holes.  All 10 turn wire wound Bourns pots as well.  TKD 4CP601 volume control as it fit the front panel perfectly.  Not sure what to do with that gaping hole but might have a MA logo etched onto some plexiglass and illuminate it. 

Here it is even busier.  The amplifier is mostly ready, just need to wire up all the test points and the 5K balance pots.  Bias supply for the HE90 socket is in place but how I'm going to mate this to the power supply I just don't know.  It has to go on the bottom of the chassis with two fairly large transformers and two PSU boards.  It's a little bit like building a ship in a bottle... 

The PSU is up next so wish me luck. 

[JimL]

Whoa!  I thought you had already re-built it.  Are you going with constant current output loads, or sticking with the resistor loads?

[spritzer]

I stuck it in storage when I was moving and kinda forgot about it.    The resistors were there so I'll use them but it would be trivial to use a CCS.  These all had resistors back in the day I want to make it as a fixed version of the stock pile of fail. 

I finished wiring up the test points and pots today so the amplifier is ready for testing. 

[Jon L]

This is Masochism at its finest..!

[Fitz]

2 minutes ago, Jon L said:

Masochism

This is the Dark Souls of amps!

[JimL]

IIRC the basic circuit is the SRX, which is fine.  Mikhail just did everything he could think of to f**k it up.

[spritzer]

Mikhail was the master of fucking up stable circuits.   

[Fitz]

Now that's a name I've not heard in some time.

[wink]

Ahhhhh Mikhail.....

 

OOOooops, wrong Mikhail.

It's this one.... right....?

 

Edited July 27, 2017 by wink