[SCompRacer]

An alternative to Bendix are MU 6900's.  I have a pair in my ModWright 9100ES.  Cost was $350 a pair, a little more than a year ago. 

In the 1960s, the Bendix Red Bank Division and remaining stock were purchased and re branded by MU Engineering. MU continued to manufacture small amounts of them to original specs with Bendix tooling at their Oceanside, California, plant.  The MU's looked and sounded identical to the Bendix 6900, so I sold the Bendix.

[ted_b]

Got everything set up last night. Thanks for the tips. I'll run the stock tubes for three more days then will switch over to the NOS ones. Headphone listening only until this weekend.

This makes me want to get my other Transporter modded as well, but I'd have to do some serious reconfiguring of my main rack.

Personally I'd get used to the stock ones but only after break-in, say the next month or so.  Any tube rolling before hearing the broken-in caps/stock tube combo (200+ hours) wil be somewhat ineffective IMHO.  My $.02

[RUR]

Ted, have you tried the Bendix 6900's in your 3910?

Ken

Ken,
No, I haven't.  Although Wayne Donnelly was ga-ga over them, many I've spoken to say they are not nearly worth their huge $$.  What say you?

Ted, I evaluated several pairs of Bendix 6900's in my 3910 this past weekend and they ranged from meh to absolutely phenomenal.  Additional evaluations are planned and I'll post more comments as circumstances permit.

Ken 

[ted_b]

Ted, have you tried the Bendix 6900's in your 3910?

Ken

Ken,
No, I haven't.  Although Wayne Donnelly was ga-ga over them, many I've spoken to say they are not nearly worth their huge $$.  What say you?

Ted, I evaluated several pairs of Bendix 6900's in my 3910 this past weekend and they ranged from meh to absolutely phenomenal.  Additional evaluations are planned and I'll post more comments as circumstances permit.

Ken 

Great!  Wild that the same tubes would vary so much from "meh" (dunno what that means  ) to phenomenal.  Keep us posted.

[DTB300]

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.

I guess this would also apply to the external PS for Modwright products since it is not usable in the TP?

[funkmonkey]

Don't know if you guys saw this yet or not, but while I was looking around for tubes, I came across this video...  I thought it was pretty cool.   If you get tired of buying tubes you could always make your own... 
(audio is in French) scroll down to the bottom for the Vid
http://paillard.claude.free.fr/

Cheers
-Funk

[Philistine]

Don't know if you guys saw this yet or not, but while I was looking around for tubes, I came across this video...  I thought it was pretty cool.   If you get tired of buying tubes you could always make your own... 
(audio is in French) scroll down to the bottom for the Vid
http://paillard.claude.free.fr/

Cheers
-Funk

Thanks for the link - it was posted a few months ago on another thread, but still it's a amazing the craftsmanship and patience they guy has.

[funkmonkey]

Just ordered a Mullard Fat Base, and matched pair of RCA clear tops to try out...  Thanks to the tips in this thread... 

I wanted to try a Holland made Phillips, but couldn't quite convince myself to part with that much money for a tube, yet...   

Cheers

[JG2]

Here is a pretty good 'buy it now' on a tested metal base GZ34. With the prices going up on these puppies, a bit over $200 with shipping isn't too bad.


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260283114113&fromMakeTrack=true&ssPageName=VIP:Watchlink:middle:us

I have no affiliation with this seller.

Someone WILL snag this tube!

[Jerrym303]

I'm probably going to put one up in that range soon.  I feel like a hog with three.  I won't be able to use them all unless I move to a 36.5 with external PS someday.  All three of mine sound fantastic.

[Bigfish]

Jerry:

Thank you again for selling me one of your Metal Base GZ-34s.  I installed it tonight and all I can say is the Metal Base GZ-34/6H30DR combination is awesome!

Ken

[sleepysurf]

Kudos to RUR/Ken, who lent me one of his metal base GZ34's to audition in my SWL 9.0SE.  Compared to my NOS black base RCA/Mullard, the metal base version is definitely a step up in bass detail, midrange clarity, and overall tonal balance.  It's incredible how much sonic differences there are between various rectifiers tubes.  Thus far I've used...
1) The stock Sovtek 5AR4- sounded fairly good until it blew, but not as detailed bass as I'd like.  Never had the chance to compare it head to head with the others.
2) A Ruby 5AR4 (which Dan sent as a replacement)- Perhaps the most detailed in the mids and highs, but a bit fatiguing after a while, and still lacking in bass.  Perhaps it needs more time for "burn-in".
3) A TAD "select" 5AR4, which I haven't listened to much- Thus far seems nicely balanced, and "smoother" than the Ruby, but likewise still a bit flabby in the bass.
4) A NOS RCA/Mullard black base- I'd rank this one just a notch below the metal base version.
5) The metal base Mullard- Definitely the most "musical" sounding of all, but I'm not sure I'd go above $200 in a bidding war for one!

On the output side, I've compared the stock Tungsol 5687's vs. the JAN Philips, but have not noticed any significant differences between them.

Next up, I plan to have a go with tube dampers.  I recently got the cheap red silicone ring types, and will likely order Herbies to try as well.

Since the Ruby and TAD lean towards the "brighter" side, I'll try the dampers there first.

Thanks again to Ken for teasing me with the sound of the metal base vintage.  At least I now have a "reference" to aim for!

[RUR]

Thanks again to Ken for teasing me with the sound of the metal base vintage.  At least I now have a "reference" to aim for!

You're most welcome, Alan.

@ Ted: Still waiting for more 6900's to evaluate in the 3910. 

[rydenfan]

It is way to quiet around here lately, we need to buy some tubes 

I am wondering if anyone here knows about the 5931 tube? It is a rare military type rectifier tube, equivalent to the 5U4GB. It is supposed to be similar to the Tung Sol 5U4GB but punchier with more dynaimcs and resolution. They seem to go for about $60. I very well might try one, but thought I would also check and see if anyone here has some experience with this tube?

[ted_b]

Once again, David, we are on the same wavelength.       My local find here (Noel,the gentleman with the 14,000 tubes) is looking for some for me, and I'll ping you if he finds any.  I guess the Sylvania are the faves of this military spec variety of the 5U4GB. 

[rydenfan]

Crazy you thought about that tube as well  I guess as Prez and VP it is our duty to kick this thread back into action 

I know where to get that tube for $60 if you are interested? Have you heard good things about it as well? I can get Sylvania Gold Brand or Westinghouse military brownbase

[ted_b]

Crazy you thought about that tube as well  I guess as Prez and VP it is our duty to kick this thread back into action 

I know where to get that tube for $60 if you are interested? Have you heard good things about it as well? I can get Sylvania Gold Brand or Westinghouse military brownbase

 

I've only read a few things, mostly the tube forum at the Asylum.  I'm actually thinking about a pair as options for the 36.5.  The metal base is sooooo good in the TP that I dare not fix what ain't broken.

[Philistine]

The metal base is sooooo good in the TP that I dare not fix what ain't broken.

If you guys find a tube that beats the metal base, or is cheaper, then I'm all ears.
Metal base 5AR4's are increasing in price, better to convert my 401k into NOS - probably worth more when I retire

[rydenfan]

I've only read a few things, mostly the tube forum at the Asylum.  I'm actually thinking about a pair as options for the 36.5.  The metal base is sooooo good in the TP that I dare not fix what ain't broken.

Of course you need a pair, you 2 box elitist 

Since I am a lowly one box 36.5 and TP owner the opposite is what I am thinking for me; having the 5AR4 in the 36.5 and that tube in the TP. I can get you two of them no problem if you want them.

[JG2]

Tube world has NOS 5931 tubes for $35 and $40.  You KNOW they're the real thing from TW.

I bought one a while ago but have been too busy to give it a whirl.

John