Crack, Seduction and FPIII - Triplets

[Laudanum]

My recent builds for the Lazy Chair headphone system.   I kept it pretty simple with all 3.  I left the top plates unfinished with the exception of painting the tansformer bell caps black.  The bases for all 3 are finished with a golden oak stain and Minwax Tung Oil finish.  The Minwax "Tung oil" finish is really a varnish and I applied it as a wipe on rather than a rub-in to get a little bit of a satin finish.  The lighting is a little different in the pictures but the bases for all 3 components do match up color / finish wise. 

Crack has the Speedball upgrade.  Mundorf MKP film caps.  Alps pot.  And I bypassed the last PS cap with a Panasonic 2.2uf that I had on hand.  I've been meaning to replace the Panny with a Solen or Mundorf but keep forgetting.  I dont think it will make a difference:  

Tubes in this photo are an RCA 6AS7 and an RCA 12BH7A for the driver:

 

[Laudanum]

Seduction has the C4S upgrade built in during initial build.  I used Obbligatto Gold Premium 1.0uF caps for the outputs.  I think that everything else is pretty much stock.  I did flip the power entry module after the fact so that I could use a 90 degreee IEC plug/cord.  I didnt think about it during the build.

Tubes are Russian NOS 6n23-EV:

 

[Laudanum]

Finally, my FPIII.  It's the Non-extended version.  I built FPIII from the start with Octal sockets for 6SN7's instead of the stock 9 pin sockets.  Output caps are Obbligato Gold Premiums, 2.2uF.  I used a .1uF Obbligato on the OD3 as well.  Mills resistors in place of the stock wirewounds.  I think that all other components are stock, as included in the kit. 

Tubes are Baldwin labeled Sylvania "Chrome Top/Dome" 6SN7GTB's.  And, the stock RCA OD3 (the lavender glow is just too cool).

My sources for this Recliner Headphone system are all budget.  A Rotel RP900 TT (Rega 2 clone) with rewired Rega RB250 arm. 
The CDP is an Ah Tjoeb! 99 tube CDP. 
And also a digital player (Wav files) that sounds surpisingly good, especially since the FPIII addition.

That's it.  I kept it pretty simple inside and out.  I had to pick my spots in terms of upgrade parts so I focused on caps and resistors in a few key places rather than upgrading parts like RCA jacks and tube sockets which would have quickly blown the budget.  Plus the Alps pot for Crack which I thought was a good bang for the buck upgrade at 14 dollars, especially in terms of low volume tracking which it does do very well.  I dont think I could be any happier with how it all turned out.  You just can't lose with Bottlehead stuff, thanks gang ... for the kits and the forum support.

 

[bainjs]

I was curious about your comment on the OD3 - "lavender glow". I didn't know the OD3 put out any glow to speak of.  How'd you do that?

Thanks

Joel

 

[Laudanum]

The "glow" is enclosed within, what I guess would be called a circular/tubular shield rather than plates???  I have a couple of Hytrons in which you really cant see much of anything as the "shield" is  completely enclosed.  You almost have to look at certain angles to see anything.  But with the RCA there are a few places where the light seeps out, most notable are two slits in the top spacer.  So while the whole tube doesnt emit a glow (bummer, it would be really cool if it did), you can see it seeping out with the RCA OD3.  I'll try to take a picture that shows it and post. 

 

[bainjs]

Showing my ignorance ... hytrons?

 

[Laudanum]

Hytron is just an old tube brand.  I have a couple Hytron OD3's as spares.

OK, a couple RCA OD3 pics.  They arent great quality and, atleast on my monitor, the color of the glow is washed out a bit,  but you'll get the idea.

 

[bainjs]

Did you change/add to the circuit to get it to light up?  My FP3 has nada in terms of glow from the OD3.  It's also an RCA.  I guess it's odd that a somewhat mature kind of guy like me would get excited to potentially get more glow from his tubes.  I remember the first time I turned it on, there was a bit of a letdown when I didn't see anything.

Joel

 

[Laudanum]

Hi Joel. 
Nope, I didnt do anything to the circuit.  Other than the 6SN7's in place of the 12AU7's and the cap upgrades, it's stock. All that entailed was a lower value resistor for proper heater voltage due to the higher current draw of the 6SN7's. That wouldnt have impacted the OD3.  Voltages are pretty much dead on as well.  I also tried one of the Hytron OD3's and it also glows the same way.  You just cant see it as well as the shield is more enclosed. 
I'm pretty sure the glow is normal because I read in a thread on some forum regarding the fact that some of the OD3's were enclosed so that you couldnt see the glow as well.  So I would ask about it in the general forum or the FPIII forum as Im sure someone more familiar with the tube could give you a definitive answer.  This is my first experience with this tube.  The only things that come to mind are that maybe they stop glowing when the get weaker ???  Or maybe there are different variants and some dont glow (maybe a different gas or halide or whatever else is inside)???
Just guessing here.  Sorry I dont have a better answer.

BTW, Im closing in on 50 years old and I think the glow is cool so you're not odd at all wanting a purplish glowing OD3.  Either that or we are both odd.  It's never supposed to stop being fun

 

[randy@matrixq.com]

That's a nice build and I like your thought process on the upgrades.  Seems like you put your money where it mattered.

My FPIII is still stock and I'm quite enamored with the OD3.  Check out my profile picture for that "Lavender Glow".

 

[Paul Joppa]

bainjs, you might post this question in the Foreplay forum. Check your voltages and post them - at least the tube pins and both ends of the large power resistors T21 to T25. The tube ought to glow, unless it's shielded by the getter flash. Do you have on of the "potato masher" mil-spec OD3s? The hide the lower half of the tube pretty well...

 

[bainjs]

I've got a couple of OD3's on order to try.  I can see the glow a'comin!

 

[bainjs]

Randall,  what brand is your OD3?

Thanks

Joel

 

[Laudanum]

That's a nice build and I like your thought process on the upgrades.  Seems like you put your money where it mattered.

My FPIII is still stock and I'm quite enamored with the OD3.  Check out my profile picture for that "Lavender Glow".

Thanks Randall.  Budget was a bit thin, especially since I needed to put some into a second TT.  Im real happy with the simple look of the kits with unfinished top plates and my wife and I both really like how the bases came out.  Bottlehead gear sounds great stock anyway.  But figured that the caps would have more sonic impact than RCA jacks and/or tube sockets.  Not that there isnt any merit in upgrading those, Im sure that there is.   I have heard a difference with different caps on other gear and crossover networks that Ive built in the past, so I figured they would be a good bet for the money.  I will eventually try a different pot in Crack to see if I hear a difference.  My non golden ears may not but I'm curious to see.

 

[Poultrygeist]

FWIW, I replaced my FPIII OD3 with a NOS Sylvania and it puts out a gorgeous glow.