Tube rolling in ModWright PS 36.5 - any thoughts?

jazzcourier · « **on:** 31 May 2008, 08:31 pm »

Those of you that have this unit know it is a masterwork.As glowing as the recent 6 moons review is it does not do it justice,in that it does not detail the holographic effect it has on vinyl reproduction.In particular the reproduction of finely recorded percussion,the deep bellow of the kettle drum in a symphonic piece to the snap,crackle and pop of an Art Blakey Pressroll.This unit creates an almost infinite soundstage.It lifts the music to new heights.
What tubes are you running in the power supply? What have you tried and what are your results in taking this unit to it's furthest limits of reproduction.I have been using the supplied nos RCA 5u4's.Choices are 5u4--5v4--5ar4--GZ37. Here is a quote from designer Dan..."I really like the 5u4 and haven't gone back to the 5AR4 in the power supply,but you may differ......" What is the holy grail 5u4 (gb] tube for the power supply? What do you like,where did you get it and what did it cost? Thanks for your comments!

ted_b · « **Reply #1 on:** 1 Jun 2008, 12:32 am »

Right now I use a pair of Tung Sol 5U4GB's in my dual mono version, and love them. I have a couple as backup, and three more coming. I also have my eye on a couple G (ST shaped) versions. They are a nice combination of the dynamics of the Philips GZ32 and the warmth of the Mullard 5AR4's. In the single version you might want to try a metal based GZ34 too. But..........you GOTTA try Reflektor 6H30 DR's in the signal tube sockets! Wow.

Thanks to David (Rydenfan), Phil (Philistine), Frank S and others..there are many posts about tube rolling in Modwright products. We've asked Dan to make a couple of stickies each for cables/tweaks and tube rolling (one each for each of the LS 36.5 and Transporter products). In the meantime just peruse the Modwright forum. You'll find our lists.

Big Red Machine · « **Reply #2 on:** 1 Jun 2008, 01:06 am »

I did what Dave said to do and am extremely happy. More than happy; ecstatic.

figcon · « **Reply #3 on:** 3 Jun 2008, 10:24 pm »

Hi all..I've had Dan's fantastic PS36.5 for about a month and have rolled a bunch of rectifier tubes. These include Tungsol, RCA and Sylvania 5U4GB's; Sylvania and Philco 5U4G's and Mullard and Sylvania 5V4G's, I've enjoyed the Sylvania 5U4G and Mullard and Sylvania 5V4G's the most. All three sound great in the preamp. I believe that most of what we will prefer will be system and user dependent, but all sound good in this thing.

ted_b · « **Reply #4 on:** 4 Aug 2008, 01:27 pm »

Well, I've been listening to the Tung Sol 5U4GB/6H30-DR combo for quite some time and I love it. So why try something new? Cuz we're sick audiophools, that's why.

I had read some good feedback on the very inexpensive Mullard-knockoffs called Tube Audio Doctor (TAD) 5AR4's ($20 each, new). They are fashioned after the Valvo Mullards of the late 50's early 60's.They have a nice brown base and come matched for a couple extra bucks. I put them in my dual mono PS a couple nights ago and gave them their first critical listen last night. They sound every bit as good as the T-S GB's with possibly even more dynamics. hwoever, I think I keep hearing, very occasionally, a small bit of noise out of the black background. I'm not sure if a rectifier would add noise (wouldn't that be a signal tube) but it could be my other tubes somewhere in the signal path. I'll listen again tonight to the same passages, then report back. It also could be better resolution that is allowing me to listen into the recording (i.e recording or microphone noise). I go on vacation beginning Friday so if I'm not reporting back by Thurs it'll be 10 days before I can get to it.

Net/net, there may be a real inexpensive alternative that betters the Mullards in certain situations.

jazzcourier · « **Reply #5 on:** 4 Aug 2008, 03:25 pm »

I too have been running the Tung Sol 5U4 GB's {with the 6H30-dr} and just yesterday i swapped the 5U4's for a pair of Sovtek 5AR4's to quench my curiosity.Everything brightened up but the sweep of the soundstage sounded a little shy on vinyl reproduction and returned to the 5U4's. I am still curious as to how some decent 5AR4's might sound,any comment on the mentioned Tube Dr. tubes vs. the Sovtek would be helpful. Even the Plump sounding Pope 6V6's in the BAT power amp didn't balance out the somewhat diminished sound.Thanks for any comments!

ted_b · « **Reply #6 on:** 1 Sep 2008, 04:41 pm »

So I've been running the inexpensive ($20-30 each) Tube Audio Doctor (TAD) 5AR4's in my 36.5 dual mono PS for the last 3 weeks or so. They have sounded very good and have a nice smooth even response to them. Some here have replaced Mullards with them as, although they are new tubes, they are based on Valvo/Mullard late 50's design. I decided that now that I am very familiar with their sound I would swap back in my Tung Sol 5U4GB's in their place. I did so yesterday afternoon and let them run for about 6 hours before I sat down to listen later last night.

The TS GB's are no doubt a better tube compliment with my setup. After having them out for so long I was assuming I would lose dynamics (it was my first sense of the TAD's) but not so. They were equivalent there. This update is no slight to the TAD's, but the TS's are a a bit richer, wetter, more organic sound, with slightly more detail and better definition down low (which is possibly where the detail is coming from). The top end has more air and may be too much for some tastes, but I prefer it. The TAD's may even go a tad (pun intended) lower, but nothing that the better low end definition of the TS's doesn't make up for. I am not sure if these sonic differences are based on topology (i.e would most any 5AR4 sound this different to a 5U4GB?) or quality.

Net/net, the TAD's are a bargain. They are going to be my tubes that I use for secondary extended use: parties or when long background listening sessions or equipment break-in is required. They are also the no-brainer as inexpensive back-ups, as they sound better than 5AS4's or the Sovtek 5AR4's (although I haven't a/b'd them...just from memory). They sounded great from day one through yesterday, and if I hadn't swapped them I would be fine....but for now the TS 5U4GB's are my reference PS 36.5 rectifier pair.

jazzcourier,
As I mentioned I did not a/b with Sovtek's but my memory tells me that the TAD's are much better and at their price point a low risk trial. The soundstage width and height of the TAD's was no slouch, but they gave up front-back depth to the Tung Sol GB's for sure.

rydenfan · « **Reply #7 on:** 1 Sep 2008, 05:51 pm »

Ted very interesting and useful information as I am getting close to adding the PS to my setup

Are the TAD 5AR4's the only 5AR4's you have tried? I am curious about actual Mullard 5AR4's versus the 5U4GB's.

I currently own one Mullard fat base 5AR4 and one Tung Sol 5UGB for my one box 36.5 and TP so I will likely buy one more of each tube so that I will have both options to listen to.

ted_b · « **Reply #8 on:** 1 Sep 2008, 06:32 pm »

David,
I tried Sovtek 5AR4's originally and didn't like them, but didn't a/b them to the TAD's. A Mullard fat base combo would be very worth a try. I have one, but not two (same with metal base, 5U4G's, etc.). I have very few pairs of rectifiers other than a boatload of addtl 5U4GB's (5 more TS's, some Sylvania's, some RCA's) I got cheaply at MDBVentures.
http://fourwater.com/audio/audio_au7.htm#5U4-GB

jazzcourier · « **Reply #9 on:** 1 Sep 2008, 06:58 pm »

Since my post on August 4th i went ahead and purchased a pair of NOS NIB "Mullard manufactured G.E. branded 1966 Blackburn plant" 5AR4'S from Bill Thomas,who offers tubes on this site.Nice tubes at a good price {100.00 each} and a great guy to work with.I truly wanted to see just how a "good" pair of 5AR4's would sound in the power supply.After a few weeks of listening i went back to the TungSol 5U4GB'S.The 5ar4 tubes added a bit of sparkle and bumped the clarity of the higher frequencies,they did sound fine but i missed the depth,warmth,richness and expanded soundstage that the 5U4gb's exhibit.Now i have found some great 6v6's for my power amp and they are adding that extra sparkle in the higher frequencies.Now,to me,the 5U4GB is THE tube for the power supply and down the line i will be searching for the best pair,but so far the TungSol is making beautiful music.
This must have been brought up somewhere down the line...the concept of like minded,same unit owners offering tubes "on loan" to each other to try out some different tubes...you can roll the tubes without rolling the dice with your money on whether a tube will sound "right" to you.As for me,i can live with a spare pair of 5AR4's sitting around in the bullpen,so to speak.Just a thought.

ted_b · « **Reply #10 on:** 1 Sep 2008, 07:16 pm »

I'd be glad to loan out any of my pairs that are not currently in use/installed. As far as GB's are concerned I don't know what is considered much better than Tung Sol, by the way. Good question.

jazzcourier · « **Reply #11 on:** 2 Sep 2008, 01:06 am »

Here is one to keep a look out for ....one tubeseller has raved about this one as his "reference" tubes...JAN CRC-RCA-5U4-G 1943 Black Base Single Side D Getter Grey Ribbed Tall Plates-Coke Bottle Shape.He bought it on Ebay i believe.These Joint Army Navy tubes have an outstanding reputation,and the 5U4's are not in major demand so someone might spot a pair for around 40.00.

kiwi_1282001 · « **Reply #12 on:** 6 Nov 2008, 08:24 pm »

Hello all, my first post in this forum.

I'm interested in thoughts from single box 36.5 owners. I auditioned the LS 36.5 this week and whilst i consider it to be a brilliant pre-amp, i found its presentation to be a bit on the 'lean' side of the spectrum. Clearly the 36.5 is not as 'tubey' and many of its competitors - neither does it (as standard at least) have the bass weight.

Have owners found a tube complement which give (vocals in particular) a little more density and a bit more bass weight? Before i return the unit to the dealer i'd like to see whether its possible to re-audition with different tubes.

Thank you.

rydenfan · « **Reply #13 on:** 7 Nov 2008, 03:01 am »

Quote from: kiwi_1282001 on 6 Nov 2008, 08:24 pm

Hello all, my first post in this forum.

I'm interested in thoughts from single box 36.5 owners. I auditioned the LS 36.5 this week and whilst i consider it to be a brilliant pre-amp, i found its presentation to be a bit on the 'lean' side of the spectrum. Clearly the 36.5 is not as 'tubey' and many of its competitors - neither does it (as standard at least) have the bass weight.

Have owners found a tube complement which give (vocals in particular) a little more density and a bit more bass weight? Before i return the unit to the dealer i'd like to see whether its possible to re-audition with different tubes.

Thank you.

To be honest, your experiences do not line up with mine but I will try and help the best I can. I agree that the 36.5 does not sound overly "tubey" but I find that to be a positive. It creates an accurate and dynamic sound. It is very detailed and has a gigantic soundstage. However, it has a sense of realness in the midrange that I have never achieved with solid state. In my search for a pre-amp I was not looking for something that created a false sense of sound, but rather something that was true to the source while not having any edgy or harsh character to it. I believe the 36.5 does this in spades.
I do not know your system at all but lean is totally opposite of my experience. I found it has a wonderfully rounded sound. Perhaps it could be your amp or speakers are the 36.5 is very revealing. When I first placed it into my system it was the richest and truest sound I had. Swapping out the stock 6H30's for the 6H30 DR's will give you a dramatic increase in bass extension and weight. You will have plenty of bass with those tubes. You could also upgrade the stock 5AR4 to a Mullard and create an even more holographic sound.
I would also be curious what you are auditioning it against and what the rest of your system is?
Hopefully this info helps and we will try and help however possible.

kiwi_1282001 · « **Reply #14 on:** 7 Nov 2008, 03:48 pm »

Quote from: rydenfan on 7 Nov 2008, 03:01 am

I do not know your system at all but lean is totally opposite of my experience. I found it has a wonderfully rounded sound. Perhaps it could be your amp or speakers are the 36.5 is very revealing. When I first placed it into my system it was the richest and truest sound I had. Swapping out the stock 6H30's for the 6H30 DR's will give you a dramatic increase in bass extension and weight. You will have plenty of bass with those tubes. You could also upgrade the stock 5AR4 to a Mullard and create an even more holographic sound.
I would also be curious what you are auditioning it against and what the rest of your system is?
Hopefully this info helps and we will try and help however possible.

Thanks for the reply rydenfan. Yes, i was looking for a more holographic sound, with some density around the vocals. Changing the stock 5AR4 to a Mullard would assist do you think? The Modwright being the high quality piece of kit it is - is being auditioned against an ARC Ref 3 and a Lamm LL2 Deluxe. The rest of the system is very revealing including ET full range ribbon planar speakers which go down to low 20Hz range.

rydenfan · « **Reply #15 on:** 7 Nov 2008, 05:21 pm »

Quote from: kiwi_1282001 on 7 Nov 2008, 03:48 pm

Thanks for the reply rydenfan. Yes, i was looking for a more holographic sound, with some density around the vocals. Changing the stock 5AR4 to a Mullard would assist do you think? The Modwright being the high quality piece of kit it is - is being auditioned against an ARC Ref 3 and a Lamm LL2 Deluxe. The rest of the system is very revealing including ET full range ribbon planar speakers which go down to low 20Hz range.

Yes, changing the stock 5AR4 to the Mullard with give you a more holographic sound and changing the stock 6H30's will give you better bass extension and punch.

If you wish to compare apples to apples then for the price of the Ref3 you should be demoing the 36.5 Dual Mono version as they retail for the same price. That would certainly add whatever extra density you are looking for. The Lamm may certainly provide a more "tubey" sound but it will not carry the detail and resolution that the 36.5 does.

miklorsmith · « **Reply #16 on:** 7 Nov 2008, 05:33 pm »

As a current owner of the Lamm LL2 Deluxe and Modwright dual-box preamps I wholly agree with ryden.

kiwi_1282001 · « **Reply #17 on:** 7 Nov 2008, 07:49 pm »

Thanks again for the reply.

I will ask the dealer to fit a Mullard and have another listen.

ted_b · « **Reply #18 on:** 19 Nov 2008, 02:17 am »

Well, it's funny how one thing leads to another. A discovery by accident.

I was tube rolling in the Modwright TP. The new PS upgrade (hyper-drive) adds a considerable amount of weight and authority to the sound, and therefore a different set of tubes pre and post upgrade. The 6H30 DR's just couldn't coexist in both the TP and the 36.5, and I'll be damned if I move them out of the 36.5

(note: in fact, other than the stock 6H30's and some other plebian variants I'm not sure there ARE other tubes to roll in the 36.5 signal section). So there i went tube rolling the signal tubes in the TP, (posted on the TP tube rolling thread...duh).

David (Rydenfan) and I chatted today about the 36.5/TP combo possibilities and he mentioned that maybe a solution would be to wait until I had a pair of higher end 5AR4's for the 36.5 and then pull the metal base out of the TP and use a GB there. (I currently use a pair of the very nice and airy Tung Sol 5U4GB's in there, and my 5AR4 inventory is made up of single versions) Hmmm....got me thinking. I DO, in fact, have a pair of very hi-end 5AR4's...the frickin metal bases!!!! BIG problem though; one of them died, or more accurately, dies frequently, while placed in the TP. But I never tried it as a second half of a pair to use in the 36.5. Maybe the current/voltage in the 36.5 is different, or maybe it's just a TP socket thing. yeah right. Well....Worth a try I guess.

I found it, pulled the other MB from the TP and set them in the PS 36.5....grabbed a black base Mullard 5AR4 and put it in the TP, and flicked on the switches. We have dual metal base liftoff!!! In fact, the TP 5AR4 was not lit, but a little jiggle and it was back in business (I think I might have a slight issue with the rectifier socket in the TP and maybe that's all it was with my "dying" metal base).

The combo of three 5AR4's was nice, a musical extravangza with nice prat (best I've ever had). The only thing missing was a little air I was used to in the soundstage depth. So I swapped out the TP rectifier and went with David's suggestion...the wonderful TS 5U4GB. YES!!!!! AND IT COUNTS!!! (Marv Albert voice). Wow! Best sound yet. Wow! (Did i say that before?) Overall, after all this, my soundstage just took a leap forward in prat, depth, air, musicality, detail and what i call "wetness" or organic qualities (acoustic harmonics sounding like acoustic instruments in the room, etc.)

Thank you, David, for the suggestion....albeit not aware that I would act on it so quickly... cuz you and I assumed I had no viable pair of 5AR4 candidates. Oh yes I do!!

rydenfan · « **Reply #19 on:** 19 Nov 2008, 02:37 am »

AWESOME! Way to take the ball and run with it!!

All along my plan has been that as soon as I add the PS, I would experiment with 5AR4's in there based off my findings in the TP. My feeling was the best combo would actually be the detail and accuracy of 5AR4's in the PS and the punch and life of the 5U4GB in the TP. It sounds like me hunch was right