[zybar]

Just thought I'd mention this as I noticed this a while back: on Brendan's Tubeworld page, if you search for the regular (non Kuhl tube) 5ar4 page, it says this about the non-metal base referred to in this thread:

($350 each Kuhl-Tube cryo-treated, sounds nearly the same as the metal base GZ34)

So here at least, he seems to be implying that there is some difference in sound to the two, and one would certainly hope so at almost double the price.  In the end only an email or phone call to him would probably flesh out the differences.  For my part, I'm considering the metal base, but man...$650...

$650 for a single tube or a pair?

I can't possibly believe anybody would pay $650 for a single tube.

George

[ted_b]

Just thought I'd mention this as I noticed this a while back: on Brendan's Tubeworld page, if you search for the regular (non Kuhl tube) 5ar4 page, it says this about the non-metal base referred to in this thread:

($350 each Kuhl-Tube cryo-treated, sounds nearly the same as the metal base GZ34)

So here at least, he seems to be implying that there is some difference in sound to the two, and one would certainly hope so at almost double the price.  In the end only an email or phone call to him would probably flesh out the differences.  For my part, I'm considering the metal base, but man...$650...

$650 for a single tube or a pair?

I can't possibly believe anybody would pay $650 for a single tube.

George

He's referring to Brendan's Kuhl Tube Philips Miniwatt metal base.  No offense, but wayyyyy too much for this.

[cAsE sEnSiTiVe]

Just thought I'd mention this as I noticed this a while back: on Brendan's Tubeworld page, if you search for the regular (non Kuhl tube) 5ar4 page, it says this about the non-metal base referred to in this thread:

($350 each Kuhl-Tube cryo-treated, sounds nearly the same as the metal base GZ34)

So here at least, he seems to be implying that there is some difference in sound to the two, and one would certainly hope so at almost double the price.  In the end only an email or phone call to him would probably flesh out the differences.  For my part, I'm considering the metal base, but man...$650...

I have that cryo'd 5ar4, as well as a metal base GZ34. I can tell you, they are NOT close. The metal base kicks its hiney. The only rectifier I have heard that bests the metal base GZ34, is the Sophia Princess mesh 274b. Unfortunately it is a very quick heating tube, and likes to see a very low value cap ahead of it. I wish like hell we could use it with the MW transporter, as it has virtually the same characteristics as the metal base, but improves upon it slightly in all areas. Best part??? Readily available @ $190.

[cAsE sEnSiTiVe]

He's referring to Brendan's Kuhl Tube Philips Miniwatt metal base.  No offense, but wayyyyy too much for this.

I got that same tube, slightly used, from Ebay for $260 incl shipping from the Netherlands. No cryo though. Can't imagine $400 worth of deep freeze could be cost effective....although I'm sure Brendan is selling a NIB tube.

 Buying this tube used from a trusted seller, is a great way to go, as these tubes would most likely outlast anything you're liable to install it into. A nice perk.

[rydenfan]

Ted, did Dan ever get back to you about your question regarding the main ac fuse?

[cAsE sEnSiTiVe]

Ted, did Dan ever get back to you about your question regarding the main ac fuse?

Yeah, I'm a little curious about that myself. It's such a benign tube on the equipment, I was surprised this happened.

[ted_b]

Yes, it is a 500mA slo blo (at least mine is), as per page 27 of the manual.  He says a 1A fast blo should be ok, though.  I'll likely return mine to CableCo and get the equivalent one.

cAsEsEnSiTiVe,
The fuse Rydenfan is asking about is NOT the tube board, it's the main ac.  The tube board fuse is 3.15A slo blo and I've replaced it twice over the 8 months or so (tmrw is 8 month anniversary..cake and ice cream).  Seems a little fragile, but no big deal.

[zybar]

I have that cryo'd 5ar4, as well as a metal base GZ34. I can tell you, they are NOT close. The metal base kicks its hiney. The only rectifier I have heard that bests the metal base GZ34, is the Sophia Princess mesh 274b. Unfortunately it is a very quick heating tube, and likes to see a very low value cap ahead of it. I wish like hell we could use it with the MW transporter, as it has virtually the same characteristics as the metal base, but improves upon it slightly in all areas. Best part??? Readily available @ $190.

Ok, I just won an auction on eBay and will have a metal base next week to compare to the Kuhl tube Mullard 1958 Black Base GZ34/5AR4 from Tube World.

George

[ted_b]

I have that cryo'd 5ar4, as well as a metal base GZ34. I can tell you, they are NOT close. The metal base kicks its hiney. The only rectifier I have heard that bests the metal base GZ34, is the Sophia Princess mesh 274b. Unfortunately it is a very quick heating tube, and likes to see a very low value cap ahead of it. I wish like hell we could use it with the MW transporter, as it has virtually the same characteristics as the metal base, but improves upon it slightly in all areas. Best part??? Readily available @ $190.

Ok, I just won an auction on eBay and will have a metal base next week to compare to the Kuhl tube Mullard 1958 Black Base GZ34/5AR4 from Tube World.

George

Good job George...and  kept it under the magic number, too.   

[funkmonkey]

Just thought I would chime in here first as a new owner of a Modwright Transporter, as I anxiously await it's arrival.  Should be here July 1st according to UPS tracking info. (Thanks Dan).

I am a complete tube-newbie so, would you guys mind making a few quick recommendations for tubes to start rolling.  Preferably in the lower cost region, though something outstanding for a little more scratch would be appreciated as well.  I haven't had a chance to read the whole thread through yet, but I certainly will.

Thanks,
-Funk

[ted_b]

Welcome to the Club!!!  Well, first the signal tubes must be the 6H30 DR's (DR's now, not any other) are $125 per pair from Parts Connexion, then get an Ebay Tung Sol 5U4G or GB at around $50 max (likely $20-40 for GB).  You'd be very happy.

Edit:  Try to win these...
http://cgi.ebay.com/2-Ex-Tung-Sol-5U4G-Coke-Bottle-Audio-Amp-Rectifier-Tube_W0QQitemZ220249185915QQihZ012QQcategoryZ73369QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[rydenfan]

Just thought I would chime in here first as a new owner of a Modwright Transporter, as I anxiously await it's arrival.  Should be here July 1st according to UPS tracking info. (Thanks Dan).

I am a complete tube-newbie so, would you guys mind making a few quick recommendations for tubes to start rolling.  Preferably in the lower cost region, though something outstanding for a little more scratch would be appreciated as well.  I haven't had a chance to read the whole thread through yet, but I certainly will.

Thanks,
-Funk

Funk, what's up buddy? Glad to finally see you posting here!  Here is my recommendation for the newbie tube pack:

Tungsol 5U4G or 5U4GB = $22
Mullard 5AR4 = $150
RCA Cleartop 6CG7'S = $48 for a matched pair

Total you will have under $200 invested and that gives you two different Rectifier Tubes to play with as well as an excellent set of Signal Tubes. You can call Brent Jessie at http://www.audiotubes.com/  and purchase these from him. Knowing what I know now, that is a great place to start.

[funkmonkey]

Cool-
thanks guys...

[Philistine]

FWIW here are my personal views (and education as a Ceramic Engineer) on cryoing:

I'm not convinced that cryoing a rectifier tube is beneficial in terms of improved sound quality or not - However I'll remain open minded. 
Cryoing got raised on another thread recently and my concern is that, even though the metallurgy theory of cryoing to relieve grain boundary stresses is well understood tubes are made from various materials and metals with differing thermal expansion coefficients.  As they cool down and heat up the different materials (glass/metal) will expand and contract at different rates, with the potential to weaken the vacuum seal and shorten its life.  I had a Tung Sol cryoed signla tube degas in the past, which makes me wary of spending $$$$ on rare tubes that are cryoed.  This will not stop me from playing with cheaper cryoed tubes, such as 6N1P's, were the risk is lower. But with rare 5AR4's and 5U4G's, that have also been around for 50 years, I wouldn't risk the potential risks of cryoing them.

Using the cryo process for musical instruments/race car parts/machine tools (all single materials) is a reliable and well understood process, non of the tube mongers understand the materials science of what they are doing. 

I would stick with a good Tung Sol 5U4G/GB or 5AR4, and forget cryoing.

[modwright]

Hi guys as a Mechanical Engineer with only a brief tour of materials science and engineering, along with the requisite level of physics as part of my Mec. Eng. education, I would have to agree that cryo'ing tubes gives me pause for the same reasons.....if only for the sake of reliability.  The key factor is the tube's vacuum.  Once that is lost, the tube is toast.  I agree that it should make the tube sound a lot better.  I have heard similar information from others more technically educated than I am in these particular areas, who felt the same.

Just my $0.02. I fully agree that Cryo'ing DOES make everything else I have heard sound better....now please don't send your whole ModWright Transporter in for Cryo however...I can't guarantee or warranty the result .

Dan W.

[rydenfan]

I received Rob's GZ37 yesterday  I am going to listen to it over the weekend. However, it may take me a bit to truly evaluate it as I have just sold my DNA-500 and in its place comes the Spectron musician III. And also I am about to sell my Dali's and upgrade to the Revel Studio2's 

[Big Red Machine]

Cool-
thanks guys...

uuuh, that neck is too straight, no natural curve.  Better see a Chiropractor.

[funkmonkey]

Cool-
thanks guys...

uuuh, that neck is too straight, no natural curve.  Better see a Chiropractor.

okay, maybe he can help with the pain I have been having in the roof of my mouth too!

Transporter arrived yesterday!!!  1 day earlier than expected!  I haven't had a chance to set it up yet (probably not until the 4th)...

[Big Red Machine]

Cool-
thanks guys...

uuuh, that neck is too straight, no natural curve.  Better see a Chiropractor.

Thought it was jewelry.  Kids these days.
okay, maybe he can help with the pain I have been having in the roof of my mouth too!

Transporter arrived yesterday!!!  1 day earlier than expected!  I haven't had a chance to set it up yet (probably not until the 4th)...

[ted_b]

Cool-
thanks guys...

uuuh, that neck is too straight, no natural curve.  Better see a Chiropractor.

okay, maybe he can help with the pain I have been having in the roof of my mouth too!

Should help with your wi-fi signal strength, though.