[Philistine]

Phil,

Be patient and you will find a tested metal base GZ34. Dan snagged his GZ34 recently as a 'Buy it Now' for less than $150 and I have found 7 for under $200. Search E-Bay Germany for the Valvo (Philips production) or E-Bay Netherlands. The Philips, Mullard, Miniwatt and Valvo branded GZ34 are are Philips production and the same tube. As these were made in Holland, you can find some pretty sweet deals if you search these sites.

Good luck!

John,
I've had my metal base GZ34 in now for about 6 weeks and compared it with a NOS Bugle Boy 5AR4, the Bugle Boy being my favorite up to this point.  I wanted to take time over the comparison and not jump to any immediate conclusions, but on this occasion the difference was significant from day 1.  It's possible for me to hear that they both have a similar sound signature, but the metal base is significantly superior - it's smoother, more relaxed, more dimensional and overall more enjoyable to listen to.  My system is now the best I've heard it, combined with the 6H30DR's my TP is now such a phenomenal source that even internet radio has become listenable and not just background music.  So thanks for the heads up on this.

Now I've got a bunch of rectifier tubes surplus to requirements - maybe I should get a 36.5 to stick them in? We can't leave David and Ted with all the multiple tube rolling fun!

Phil
   

[rpf]

So, as for the metal base GZ34/5AR4 versus the HW GZ37... This is where I am convinced I am going to lose my mind. The 5AR4 has a bit more of a robust sound to it. It is slightly more holographic and warm/rich. The GZ37 is a little more refined and detailed. The GZ34 will be ever so slightly congested on larger passages compared to the GZ37. I would say the GZ34 has a bit more of an initially alluring sound but over time seems to give me a bit of listening fatigue. You cannot even begin to imagine the amount of agonizing and scrutinizing that has taken place over the last few days  It is near impossible to pick a favorite here as they each do different things incredibly well and each have a different, yet equally addictive sound quality. Since my Dali's have a bit of a warm and live sound to them for the moment I am choosing to go with the GZ37, but that could easily change tomorrow  Tough call between these two wonderful tubes...

I find the same differences in comparing my Amperex Bugle Boy 5AR4/GZ34 to the HW GZ37 except that in this case the HW is more holographic than the Bugle Boy.

[cAsE sEnSiTiVe]

John,
I've had my metal base GZ34 in now for about 6 weeks and compared it with a NOS Bugle Boy 5AR4, the Bugle Boy being my favorite up to this point.  I wanted to take time over the comparison and not jump to any immediate conclusions, but on this occasion the difference was significant from day 1.  It's possible for me to hear that they both have a similar sound signature, but the metal base is significantly superior - it's smoother, more relaxed, more dimensional and overall more enjoyable to listen to.  My system is now the best I've heard it, combined with the 6H30DR's my TP is now such a phenomenal source that even internet radio has become listenable and not just background music.  So thanks for the heads up on this.

Now I've got a bunch of rectifier tubes surplus to requirements - maybe I should get a 36.5 to stick them in? We can't leave David and Ted with all the multiple tube rolling fun!

Phil
   

Philly, I'm running precisely the same setup in the TP as you are. Sounds damn good, doesn't it?

[sleepysurf]

Had an interesting epiphany today.  I finished installing my room acoustic treatments this afternoon (corner bass trap, plus four 2" fiberglass acoustic panels).  I also "tweaked" my Summits forward tilt so the stat panel is fully upright (not tilted back as per the default).  The combination of all this yielded a much deeper soundstage, with better imaging and tighter bass, but the midrange and treble (with the Ruby 5AR4) was now too detailed and bright... very fatiguing.  I added a second tube damper ring, with little improvement.  I then rolled back to my Mullard 5AR4 (which had previously sounded a bit "mushy" in my setup), and voila, SONIC NIRVANA!  Bass is now extremely detailed, and the midrange and highs are glorious.  Nothing else in my system has changed, so this experiment reaffirms the critical role of room acoustics and speaker positioning in the overall scheme of things.  Don't forget those variables when tube rolling!

[Philistine]

John,
I've had my metal base GZ34 in now for about 6 weeks and compared it with a NOS Bugle Boy 5AR4, the Bugle Boy being my favorite up to this point.  I wanted to take time over the comparison and not jump to any immediate conclusions, but on this occasion the difference was significant from day 1.  It's possible for me to hear that they both have a similar sound signature, but the metal base is significantly superior - it's smoother, more relaxed, more dimensional and overall more enjoyable to listen to.  My system is now the best I've heard it, combined with the 6H30DR's my TP is now such a phenomenal source that even internet radio has become listenable and not just background music.  So thanks for the heads up on this.

Now I've got a bunch of rectifier tubes surplus to requirements - maybe I should get a 36.5 to stick them in? We can't leave David and Ted with all the multiple tube rolling fun!

Phil
   

Philly, I'm running precisely the same setup in the TP as you are. Sounds damn good, doesn't it?

Yes, the combination in the TP is really something special, I've never heard music sound so good.
All the reviewers that have given good reviews on the TP with the 'OEM' tubes that Dan supplies would be completely blown away by this combination. 

[ted_b]

John,
I've had my metal base GZ34 in now for about 6 weeks and compared it with a NOS Bugle Boy 5AR4, the Bugle Boy being my favorite up to this point.  I wanted to take time over the comparison and not jump to any immediate conclusions, but on this occasion the difference was significant from day 1.  It's possible for me to hear that they both have a similar sound signature, but the metal base is significantly superior - it's smoother, more relaxed, more dimensional and overall more enjoyable to listen to.  My system is now the best I've heard it, combined with the 6H30DR's my TP is now such a phenomenal source that even internet radio has become listenable and not just background music.  So thanks for the heads up on this.

Now I've got a bunch of rectifier tubes surplus to requirements - maybe I should get a 36.5 to stick them in? We can't leave David and Ted with all the multiple tube rolling fun!

Phil
   

Philly, I'm running precisely the same setup in the TP as you are. Sounds damn good, doesn't it?

Yes, the combination in the TP is really something special, I've never heard music sound so good.
All the reviewers that have given good reviews on the TP with the 'OEM' tubes that Dan supplies would be completely blown away by this combination. 

Phil/cAsE,
My same winning combo, too, with my Bent TAP pre (when 36.5 was at shop). 

However, with my 36.5 the dual DR's were too much (thanks David), and so the Raytheon 6Cg7 black plates have taken the DR's spot in the TP.  That metal base is da bomb, though.  David is sending me Rob's GZ37 HW to try, but I think the metal base is there to stay.  We'll see.   

On a related subject (Modwright and tubes) I've reinstalled my prized Modwright Denon 3910 Platinum Sig universal (for hirez 2 channel only use right now).  Tube rolling in that is a pain due to the nine screws in the cover, but my Amperex PQ (USA) 1984 orange lettered 7119's sound so good in it I may not try the Tung Sol 5687 or GE Jan 7044's I have.  I thought Patricia Barber's Companion sounded great in redbook/TP.  Wow, the SACD on the 3910 is incredible.  The rig is warmer right out of the gate, but it's ok; I like the diversity.  And I haven't even gotten the PS tube -rectified yet (sending to Dan late August for the PS upgrade and some tweaks)!

Hail all Modwright!

[Philistine]

Ted, what rectifier tube are you using in the 36.5 along with the DR's?  I see in a previous post you were trying a pair of the TAD 5AR4's - if these work out it's going to save me a boat load of $$$$ when I take the plunge with the 36.5!
Phil

[rydenfan]

Phil, Ted uses dual Tung Sol 5U4GB's because he has the dual mono power supply for the 36.5. I use a Mullard 5AR4 in the single box 36.5

[rydenfan]

However, with my 36.5 the dual DR's were too much (thanks David), and so the Raytheon 6Cg7 black plates have taken the DR's spot in the TP.  That metal base is da bomb, though.  David is sending me Rob's GZ37 HW to try, but I think the metal base is there to stay.  We'll see.   

Actually, I just sent Rob a PM so I will be sending you my HW GZ37  I am also going to send you the Mazda/Brimar 6CG7's because they are a pretty different tube for a 6CG7 (more lively and a bit more musical) and I will be curious to see your impressions of them. I figure once you get used to the GZ37 you could try the signal tubes with the, why not right??  Everything is packed up and will be going out to you tomorrow.

[jwes]

OK all, you have sold this tube newbie...  I have on their way a NOS Mullard Fat black base, and a pair of NOS 6H30 DR's...  Won't be quite the same as the metal base, but prices for that tube seem insane to me (over $600?).  Hopefully this combo approximates reasonably closely your experiences and I'm really psyched!   

[ted_b]

OK all, you have sold this tube newbie...  I have on their way a NOS Mullard Fat black base, and a pair of NOS 6H30 DR's...  Won't be quite the same as the metal base, but prices for that tube seem insane to me (over $600?).  Hopefully this combo approximates reasonably closely your experiences and I'm really psyched!   

Hopefully you go the DR's from Parts Connexion?  You'll love 'em.

Phil,
The TAD's are due here any day.  Currently, yes, I use T-S GB's.

David,
Thanks.  Congrats on the HW.  I'll listen to the Mazdas but the Raytheons are so much better than my dozen or so other 6CG7's.  Once again...we'll see. 

[jwes]

OK all, you have sold this tube newbie...  I have on their way a NOS Mullard Fat black base, and a pair of NOS 6H30 DR's...  Won't be quite the same as the metal base, but prices for that tube seem insane to me (over $600?).  Hopefully this combo approximates reasonably closely your experiences and I'm really psyched!   

Hopefully you go the DR's from Parts Connexion?  You'll love 'em.

I did indeed!   

[Jerrym303]

Ted,

Is there a source for the Raytheons?

[rydenfan]

David,
Thanks.  Congrats on the HW.  I'll listen to the Mazdas but the Raytheons are so much better than my dozen or so other 6CG7's.  Once again...we'll see. 

The Mazda's are more just for the fun of it since I am sending you tubes anyway. They sound quite different than the other 6CG7's I have had so I just figured I would send them along. You will have them and the HW GZ37 on Thursday 

On a side note, since I am going with the GZ37 I do not anticipate keep the NOS metal base GZ34 I have. I have a 30 day trial on it from where I bought it and can easily send it back. However, I thought someone here may be interested in acquiring it from me rather than me returning it? If anyone wants it just shoot me a PM...

[ted_b]

Ted,

Is there a source for the Raytheons?

I got mine for a song, from MDB Ventures.  Make sure to ask for the "good ones" (i.e black plates that tested well).  Their lists change almost daily. 

[sleepysurf]

Just got my TAD 5AR4 yesterday (from Antique Electronic Supply), and upon first listening, it falls between the Mullard and Ruby in overall tone.  The bass is very detailed, perhaps (slighly) surpassing the Mullard, but the Mullard has a warmer midrange, and smoother top end.  The TAD bests the Ruby across the spectrum.  I'll do more extended listening this weekend, and see how the TAD sounds with a ring damper (or two).

[sleepysurf]

...Modwright Denon 3910 Platinum Sig universal (for hirez 2 channel only use right now).  Tube rolling in that is a pain due to the nine screws in the cover...

I'm curious, how many screws to remove the cover on the 36.5?  The SWL 9.0 has TEN screws, so I've left the cover off until I decide on my final tube mix.   Sure wish Dan (or somebody else) offered an after-market cover upgrade for the SWL to facilitate tube-rolling!!

[rydenfan]

...Modwright Denon 3910 Platinum Sig universal (for hirez 2 channel only use right now).  Tube rolling in that is a pain due to the nine screws in the cover...

I'm curious, how many screws to remove the cover on the 36.5?  The SWL 9.0 has TEN screws, so I've left the cover off until I decide on my final tube mix.   Sure wish Dan (or somebody else) offered an after-market cover upgrade for the SWL to facilitate tube-rolling!!

The 36.5 is 4 very simple screws. It takes almost no time at all to remove the cover and replace it. I have a feeling Dan could have a top machined for you that would allow access to the rectifier it that is something you truly wanted.

[ted_b]

...Modwright Denon 3910 Platinum Sig universal (for hirez 2 channel only use right now).  Tube rolling in that is a pain due to the nine screws in the cover...

I'm curious, how many screws to remove the cover on the 36.5?  The SWL 9.0 has TEN screws, so I've left the cover off until I decide on my final tube mix.   Sure wish Dan (or somebody else) offered an after-market cover upgrade for the SWL to facilitate tube-rolling!!

The 36.5 is 4 very simple screws. It takes almost no time at all to remove the cover and replace it. I have a feeling Dan could have a top machined for you that would allow access to the rectifier it that is something you truly wanted.

yeah, it's just a top hatch kind of thing.  Very simple.  They're allens but you could even replace with thumbscrews.
 

[rydenfan]

My NOS metal base GZ34 has been sold guys. I hope the guy that bought it joins us at AC as he has quite a nice system