Let's talk about Tube Rolling in the Modwright LS100 Pre

dminches · « **Reply #20 on:** 14 Dec 2011, 04:13 pm »

The labeling itself doesn't matter since many of the tube manufacturers made tubes for other companies. Having said that, you have to trust that the information you are getting is accurate. I recently bought a pair of Rogers-labeled Mullards with DD getters for a very good price since they were labeled Rogers and not Mullard. Those who know the Mullard tube and plate construction well will know for sure what's what. I don't know this stuff well enough to eyeball it. This is one reason why people stick to the on line stores like audiotubes or tube world. You may pay a little more but you know for sure what you are getting.

SoCalWJS · « **Reply #21 on:** 14 Dec 2011, 05:33 pm »

This is getting confusing. Never knew there were so many variations of these things. I viewed the youtube video on the Audiotubes website showing several of the different styles through the years.

I take it that most/all GZ34/5AR4's fit the LS100 in spite of the slightly different pin configurations.

Does the # of or configuration of the pins make a difference?

dminches · « **Reply #22 on:** 14 Dec 2011, 06:06 pm »

Where did you read that there were different pin configurations?

SoCalWJS · « **Reply #23 on:** 14 Dec 2011, 06:16 pm »

Quote from: dminches on 14 Dec 2011, 06:06 pm

Where did you read that there were different pin configurations?

The Audiotube website shows a youtube video with the bottoms of different GZ34 tubes. One is shown with 5 metal pins around the center plastic pin - 3 are together, then the other 2 equally spaced apart. Another tube has 4 metal pins equally spaced apart. Also, the center plastic pin may or may not have a hole in the bottom.
http://www.audiotubes.com/audtube.htm
(scroll about a third of the way down the page)
Also checked several on ebay - some with 4 pins, most with 5.

dminches · « **Reply #24 on:** 14 Dec 2011, 06:54 pm »

As long as they are true GZ34s then they are fine.

wilsynet · « **Reply #25 on:** 16 Dec 2011, 03:54 am »

Adding a bit more ...

It's a Mullard if it was made by Mullard, although you should be careful of so-called Mullard re-issues which is Sovtek having purchased the Mullard brand from Philips in 2007. But assuming it really was made by Mullard but it has a different label on it, back in the day, a number of the tube manufacturers were happy to OEM on behalf of other tube manufacturers or electronics makers.

As for myself, I don't know the ins and outs of who made what when and whether this tube labeled a Siemens is really an Telefunken. I can either trust what the Audiogon seller says is true, do my own research to confirm (I don't know how you would do that), or buy from a super reputable seller. I usually just buy from a super reputable, well known seller.

SoCalWJS · « **Reply #26 on:** 17 Dec 2011, 12:55 am »

I ordered a Mullard 4 Notch from Audiotube which should have shipped today. Santa will be bringing me the Rectifier along with the Black Treasures. Should be a HAPPY NEW YEAR!!

SoCalWJS · « **Reply #27 on:** 19 Dec 2011, 10:52 pm »

They're here, they're here!!

.... but my wife says I have to have them wrapped and under the Christmas tree for Christmas morning.

...... but, but, but - I'm missing out on a hundred hours of break-in time.

Toon · « **Reply #28 on:** 20 Dec 2011, 03:30 am »

Parts Connexion are selling NOS '70s Mullards (not Mullard-branded, but they have the ID marks and some Googling confirmed they are actually military spec, so potentially the pick of the crop) for $120 - and until a few days ago had 20% off that (probably should've mentioned it earlier...

). A self-professed tube guru told me a rectifier tube wouldn't make any audible difference in a preamp ... boy, was he wrong.

wilsynet · « **Reply #29 on:** 20 Dec 2011, 07:13 am »

I have frequently heard the opposite -- a good rectifier can make a big difference.

Toon · « **Reply #30 on:** 20 Dec 2011, 12:04 pm »

Quote from: wilsynet on 20 Dec 2011, 07:13 am

I have frequently heard the opposite -- a good rectifier can make a big difference.

That's why I said he was wrong - the Mullard made a very significant improvement in my LS100, just as others here have stated.

Alleye · « **Reply #31 on:** 20 Dec 2011, 02:46 pm »

Toon? I have a LS100 and I'm relatively new to the "world of tubes" but how did you track that the ID Marks were military spec? I'm starting to research tube rolling in the 100, but feel like I'm missing the information/knowledge necessary to make an informed decision/purchase. Any insight would be greatly appreciated! Thanks and Happy Holidays!

Toon · « **Reply #32 on:** 24 Dec 2011, 07:53 am »

Quote from: Alleye on 20 Dec 2011, 02:46 pm

Toon? I have a LS100 and I'm relatively new to the "world of tubes" but how did you track that the ID Marks were military spec? I'm starting to research tube rolling in the 100, but feel like I'm missing the information/knowledge necessary to make an informed decision/purchase. Any insight would be greatly appreciated! Thanks and Happy Holidays!

Alleye - with so many knowledgeable contributors to this thread, I'm the last person you should be asking!

When the tube arrived and didn't carry any of the expected branding, just did some Googling to confirm I hadn't been ripped off. The tube was marked CV1377 (the military designation for a GZ34, it seems), with 'F32' and 'B' (for Blackburn) printed on the back confirming it as a Mullard. It was the cheapest price I've found for a NOS Mullard after a fair bit of searching, even without the 20% discount, and a reliable vendor too with cheap postage.

SoCalWJS · « **Reply #33 on:** 31 Dec 2011, 01:45 am »

Got 'em installed - now the long wait for break-in.

About 50 hours so far.......

mraudio · « **Reply #34 on:** 31 Dec 2011, 02:26 am »

You're going to LOVE this combo of tubes. Same as what I have. Grant Fidelity says 150-300 hours for the Black Treasures. Mine took well over 400 hours to settle in, but boy are they NICE and worth the wait!!!

Alleye · « **Reply #35 on:** 26 Jan 2012, 04:33 am »

Any update from SoCalWJS and the BTs?

I just put a pair of Psvane CV181-Ts in tonight. Too early to tell, but right out of the gate they seem to be quite "different" compared to the stock Tung-Sols.

SoCalWJS · « **Reply #36 on:** 28 Jan 2012, 06:46 pm »

Wish I could give a good update. I think I'm trying to do too many things at once......

I was nearing 300 hours on the new tubes and everything was starting to come together. The new tubes were definitely different, and overall an improvement. I was hearing more music than before. When there were duets, it was easier to hear each voice. The instruments were sounding better - more natural.
I think the greatest improvements were in the areas of soundstage and micro dynamics.
Everything really starting to shape up.

Then I changed the settings of the internal crossovers on my LS-6'es. BIG improvement in bass. Mid bass MUCH better, better low end extension.
............ BUT.................
Where did my soundstage go? Depth has vanished!

Asking lots of questions on other sub forums, and I think a serious re-do in setup/room treatments is about to begin.
This truly can be a frustrating hobby.

dminches · « **Reply #37 on:** 28 Jan 2012, 09:30 pm »

LS-6s? Are those your speakers?

BTW, do you have your speaker wires on your amp and speakers crossed (+ to - and vice versa)? I think you should since the LS-100 in phase inverted. Just checking.

mraudio · « **Reply #38 on:** 28 Jan 2012, 09:41 pm »

Make sure your speaker wires are switched at EITHER the amp OR speaker, but not both. One or the other.

From the LS100 Owner's Manual:

"Design is phase inverting and this may be addressed by reversing polarity at both speaker cables, either at amp(s) or speakers."

SoCalWJS · « **Reply #39 on:** 28 Jan 2012, 09:52 pm »

Quote from: dminches on 28 Jan 2012, 09:30 pm

LS-6s? Are those your speakers?

BTW, do you have your speaker wires on your amp and speakers crossed (+ to - and vice versa)? I think you should since the LS-100 in phase inverted. Just checking.

Yup, the Focus LS-6.
I do have the speaker wires reversed at the speakers - communicated with MW and said not to worry about the HT passthrough being out of phase.