Octal tube rolling in LS 36.5???

ted_b · « **on:** 6 Feb 2009, 03:01 am »

As many of you know we Modwright Transporter tube rolling fans have had significant success in adding a new variety to the TP tube rolling game...octals! Wayne (Bolder Cable) has developed a couple of prototype 9-pint-to-octal adapters, and they work great! The variety of 6SN7's we've rolled instill a musical warmth and organic quality that the 6CG7/6N1P varieties just can't touch. So.........David (Rydenfan) and I were chatting tonight, and he came up with an interesting idea. What if we tried a similar thing for the LS 3.65 (albeit with the top off, of course, until success is generated and a need for some hole cutting is legitimized). Why? Cuz it's there.

The only real candidates I've ever had success with, in the 36.5 signal tube sockets, are the 6H30 variety, including the punchy and tight super tube DR variety. Tubes like the 6CG7's, candidates for the TP, seem to simply produce noise in the 36.5 I've ping'd Dan tonight as to what might be safe in the octal galaxy. In the meantime I've found that the 6H30 comes in an octal version, but that seems a redundant exercise. Any of you tube experts out there come up with safe other candidates that we could propose to Dan?

rpf · « **Reply #1 on:** 6 Feb 2009, 05:46 am »

Interesting idea, guys. It's nice to be able to tailor the sound of a piece for different material or even one's mood.

Also because only the DR versions of the 6H30 sound musical (while the new stock is strident and aggressively forward) - at least in the one box 36.5 - and they're now $160. - $200. apiece from the only two dealers I'm aware of in the US that currently have them. The price has skyrocketed twice in the last 8-9 months as availability has plummeted, leaving one to doubt if any dealer will have them in the not too distant future. I've scoured ads and added a few more pairs to the two pairs I had previously - at significantly less than the above astronomical prices - but still. A wider choice would be much welcomed.

ted_b · « **Reply #2 on:** 6 Feb 2009, 02:13 pm »

After further thought it might be wise to post this:

do not try this at home!

This is from Modwright, anytime I've talked about tube rolling and leaving the top off:
"With the lid off the B+ runs close to 300volts DC (potentially lethal) and is a bad situation if or when someone or their child puts their fingers in the chassis."

Synopsis: Not a good idea!!!

The lid of the 36.5 would not be an easy or pretty cut with the MW design cut into the top. Anything is possible so we'll see what Dan thinks.

RUR · « **Reply #3 on:** 7 Feb 2009, 04:14 pm »

Coincidentally, another member and I have been talking about trying the EML mesh in lieu of the MB GZ34 in either/both the LS36.5 or the PS9.0 used on the 3910/9100ES. If either works out to our satisfaction, he has connections who can fabricate proper covers with holes, perhaps even with, Dan permitting, the fancy MW logo used on the 36.5. How well this works out or whether it's viable/affordable in small quantities remains to be seen.

Has anyone tried the EML in the 36.5 or players?

ted_b · « **Reply #4 on:** 13 Feb 2009, 04:40 am »

If I could get a couple of Modwright AC'ers (like George, David and or Phil?) to loan me theirs I'd love to try DUAL EML's in the 36.5 PS!!

THAT would be something, I think. I mean, I have dual metal bases in there now....

rydenfan · « **Reply #5 on:** 13 Feb 2009, 01:45 pm »

Ted, as you know you can certainly borrow mine. I just need to get one first

I am hopeful they come in soon...

zybar · « **Reply #6 on:** 13 Feb 2009, 01:51 pm »

Quote from: ted_b on 13 Feb 2009, 04:40 am

If I could get a couple of Modwright AC'ers (like George, David and or Phil?) to loan me theirs I'd love to try DUAL EML's in the 36.5 PS!! THAT would be something, I think. I mean, I have dual metal bases in there now....

I would Ted, but I don't own the EML tube.

George

Philistine · « **Reply #7 on:** 13 Feb 2009, 02:18 pm »

Guess that just leaves me Ted, I'm always open to offers

ted_b · « **Reply #8 on:** 13 Feb 2009, 02:52 pm »

Thanks guys. I guess there are only a few of us EML'ers huh? And the tube is nowhere on the used market. Oh well.....it's a sign from God that i should just sit back right now and enjoy the music.

rpf · « **Reply #9 on:** 13 Feb 2009, 08:03 pm »

Quote from: ted_b on 13 Feb 2009, 02:52 pm

Thanks guys. I guess there are only a few of us EML'ers huh? And the tube is nowhere on the used market. Oh well.....it's a sign from God that i should just sit back right now and enjoy the music.

Can't let you off the hook that easily, Ted

. You can borrow mine. I put it in the 36.5 today as the 9100 is going out to Dan for repair (I'm using my friends' extra player - an APL 3910 with 6 DACs/channel and a ECC99 tube) and will report on it at the end of the weekend. In the meantime shoot me a PM with your address and I'll send it out on Monday.

ted_b · « **Reply #10 on:** 13 Feb 2009, 08:08 pm »

Well, in the immortal words of Emily Litella..."nevermind". The EML's are too fat at the base to fit into the PS; i.e the chassis is deeper than the TP and although the hole is the same size the glass begins to widen too quickly for the depth.) Would require an "elevator" socket of some sort. I suppose i could test with top off but boy would that be dangerous.

Thanks anyway RPF. VERY interested in what you think of the megabuck mega-dac'd APL. 6Moons liked the MW TP better, I believe.

AB · « **Reply #11 on:** 13 Feb 2009, 08:38 pm »

Quote from: ted_b on 13 Feb 2009, 08:08 pm

Well, in the immortal words of Emily Litella..."nevermind". The EML's are too fat at the base to fit into the PS; i.e the chassis is deeper than the TP and although the hole is the same size the glass begins to widen too quickly for the depth.) Would require an "elevator" socket of some sort. I suppose i could test with top off but boy would that be dangerous.

Thanks anyway RPF. VERY interested in what you think of the megabuck mega-dac'd APL. 6Moons liked the MW TP better, I believe.

I assume you tried the EML tube in your 36.5 PSU, Ted? I figured - by looking at all the pics here - that this would be the case but I couldn't know for sure. About how much more "hole" would you need to run the EML?
I have a machinist friend who is ridiculously skilled that could fix that hole no problem. I have already talked to him about adding holes to the PS 9.0 covers I have here.

And when you did try your EML in your 36.5 for fit, did it not interfere with the caps on the PSB?

ted_b · « **Reply #12 on:** 13 Feb 2009, 10:17 pm »

AB,
My EML-in-PS idea was a theoretical one until I tried to fit one today. As you know the PS is a dual mono so to truly "try" the EML's requires 2 of them. My try, with my single EML, was only for fit. Not sure what you mean about the PSB's. The depth of the PS requires a larger hole for the fat EML. I haven't tried to figure out how much larger. I gave up for now.

AB · « **Reply #13 on:** 13 Feb 2009, 10:41 pm »

Quote from: ted_b on 13 Feb 2009, 10:17 pm

AB,
My EML-in-PS idea was a theoretical one until I tried to fit one today. As you know the PS is a dual mono so to truly "try" the EML's requires 2 of them. My try, with my single EML, was only for fit. Not sure what you mean about the PSB's. The depth of the PS requires a larger hole for the fat EML. I haven't tried to figure out how much larger. I gave up for now.

I have a pair of EMLs coming and my plan is to try them in the 36.5. As I wrote earlier, I assumed the holes would be too small for the EML and I just wanted to be sure you confirmed that that's the case. I'll try the EMLs with the top off but I am also concerned that the tubes might contact the big caps that sit very close to the tube sockets on the PCB. (Ooops, I typed PSB previously.) But this might not be the case at all. I'll check it once the tubes are here.
Cutting the holes shouldn't be too difficult but I won't do anything until I am sure the EMLs are keepers.

ted_b · « **Reply #14 on:** 13 Feb 2009, 10:43 pm »

Ah, sorry. Now I understand. A pair coming? Kewl!! Let us know.

BTW, it's not going to be a huge cutting job (although any cutting on that gorgeous but thick lid is a chore I'm sure). The EML's touch the sockets, just won't make the connection. I bet a quarter to half inch will do (to allow some heat dissipation, as per John's earlier warning on the TP thread).

AB · « **Reply #15 on:** 16 Feb 2009, 07:57 pm »

I am not sure and I will ask Dan, but it might be possible to raise the PCB that the rectifier tubes mount on with taller stand offs. This would put the sockets closer to the lid and maybe allow the EML to fit without cutting the lid.
The only thing I can think of that would interfere with this are the lengths of the various leads into and off of these PCBs and the height/clearance of the taller caps that sit next to the sockets.

Anyone care to check approximately how much higher the sockets need to be for the EML to work?

rpf · « **Reply #16 on:** 23 Feb 2009, 11:42 pm »

Quote from: ted_b on 13 Feb 2009, 08:08 pm

Well, in the immortal words of Emily Litella..."nevermind". The EML's are too fat at the base to fit into the PS; i.e the chassis is deeper than the TP and although the hole is the same size the glass begins to widen too quickly for the depth.) Would require an "elevator" socket of some sort. I suppose i could test with top off but boy would that be dangerous.

Thanks anyway RPF. VERY interested in what you think of the megabuck mega-dac'd APL. 6Moons liked the MW TP better, I believe.

The APL I have is the Denon 3910 with 6 AKM DACs per channel and one ECC99 tube. Not the Esoteric based model (with 20 DACs per channel?). Very, very good, of course, particularly as regards spatial definition: you really get a sense of the dimensions of the venue. It is, however, more neutral than the Modwright Sony 9100 I'm used to, i.e., has a little less harmonic richness. The APL Denon is not a good combination with the EML 5U4G in the 36.5 (single box - I ran it with the top off). The EML is also very neutral and the combination was a step or two on the lean side.

Rob

ted_b · « **Reply #17 on:** 24 Feb 2009, 01:08 pm »

There is no thread for signal tube rolling in the LS 36.5. This post is another example as to why.

Although not octals, I tried tube rolling signal tubes in the 36.5 last night...to no avail again. I have the very dynamic 6H30 DR Supertubes in there now, and was reading on another site (Audio Valve) that they were using 6N6P's (some of our TP rolling candidates) and 6H30's almost interchangeably in their documentation for a new 2 chassis pre (goofy ugly pre, btw). So I thought, well, Phil and others really like this tube, I've got several of them laying around, so I'll try.

For those with 36.5's you probably notice a "tube rush" sound when first powering on and after the 45 second muted delay. The sound lasts maybe 10 seconds. it's a normal thing as the tube and circuitry heat up. Well, with this attempt at tube rolling 6N6P's the tube rush never went away. It's the same result that I had with 6CQ7's. I'm left with major tube hiss (HT bypass is dead silent, btw). Dunno, but so far the only tubes that seem to work in the 36.5 are the variants of the 6H30 9(which I thought the 6n6P was, according to Audio Valve). It's perplexing cuz the 6H30 fits nicely in the MW TP tube rolling list as well, but so do dozens of other nine pins (6BQ7, 6CQ7, 6N1P, 6N6P, etc). ??

ted_b · « **Reply #18 on:** 26 Feb 2009, 04:44 pm »

I tried again last night, with 6BQ7's, but still no luck....major tube hiss. I then went back to the standard 6H30's but the pre lost a lot of lower midrange energy, so the DR's are still king.

rpf · « **Reply #19 on:** 26 Feb 2009, 04:46 pm »

Maybe Dan can shed some light on this?