Welcome, Guest. Please Login or Register
Decware Audio Forums
10/01/14 at 11:41:59


Pages: 1 2 3 ... 5
Send Topic Print
Torii MK4 - Tube Rolling and Some Observations (Read 8950 times)
Lord Soth
Seasoned Member
****


I'm an American
BadAss!

Posts: 256
Torii MK4 - Tube Rolling and Some Observations
11/16/13 at 18:38:26
 
The following is meant to provide some feedback on the new Torii MK4 and on my (input) tube-rolling attempts.

I finally burned in my Torii MK4 for 100+ hours.
So, IMHO, the sonics have stabilised enough for me to report on my tube-rolling attempts.

My Audio Chain consists of

Oppo BDP 95
-> Soundsilver Symmetry Interconnects
-> Torii MK 4
-> Clearday Double Shotgun Speaker Cables
-> Alesis Monitor One Mk2 (Passive) Speakers (TEC 1994 Winner)

Tubes Used (Kept Constant during input tube-rolling)

Rectifier : Brimar 5R4GY "D' Getter
VR Tubes : RCA 0A3 "D" Getter,
                RCA 0C2 "0" Getter (any "D" getter versions out there???)
Output Tubes : GEC KT66 Gray Glass "D" Getter

Observations
1. The Torii MK4 is very transparent.
I also have a SE based EL34 tube amp (6 Moons Realisation award winner) which is also very clear sonically.
Both have the same resolution so Steve did not "BS" us when he made the bold claim that the PP Torii MK3 (and now 4) amp has the transparency of an SET based amp.

2. Because of the sonic transparency, in my system, the "best" sounding input tube would therefore be a "warm" one.
I rolled the following input tubes

(a) Philips (Holland) E88CC SQ Gray Shields "O" Getter
(b) Telefunken E88CC <> "O" Getter" Gray Shields
(c) Lorenz Stuttgart 3 Mica CCa "O" Getter Gray Shields
(d) Mullard (Holland) PCC88 Pinched Waist "D" Getter Gray Shields

No major surprises, the best sounding is the Pinched Waist, (d) above.

Tube (a) Had a nice touch of tube warmth but was not warm enough in my audio chain.

Tube (b) Had wonderful mids (and presence) but the bass was really lacking

Tube (c) Turned my Torii MK4 into the "Mystery amp"
High Resolution (HD Tracks) FLAC files sounded fantastic.
Low res Redbook CD FLAC were sonically atrocious.
If I lived on only High Resolution FLAC files, this would be my ticket.

Tube (d) Is the "Best" because it retained the sonic strengths of (a) to (c) whilst it overcame all the various shortcomings the above-mentioned tubes.

The Pinched Waist had
(i) More tube warmth than (a)
(ii) Had the glorious mids of (b) but was not lacking in the bass department
(iii) Was more forgiving than (c) above.
My low res sonic files did not sound like crap.
In fact, they sounded so good and non-fatiguing, I listened to low res files until 4 in the morning during one of my sessions.

Input Tube Recommendations (and musings)
My audio chain consists of pure silver interconnects and speaker cables so a warm input tube sounds best.
Any other CCa (e.g. Siemens) type of tube is likely to create an overdose of sonic transparency.

3. The Torii MK3 was built based on EL34 tubes.
On the new Torii Mk4, if you use a fat coke bottle rectifier (e.g. 5U4G or 5R4G) and 2 of those fat bottle output tubes (e.g. KT66), during installation, the tubes are likely to "say cheers" to one another!
After installation, the ventilation gap was only around 1-2 cm.
I hope this does not affect the tube life of my NOS tubes, I would have preferred a ventilation gap of at least 1 inch.

4. Sonic Depth and Width
The Torii MK4 has very good sonic depth and width.
The input tube also plays a part in affecting the size of the soundstage.

5. Positive Feedback Switch
My speakers did not whistle so it is compatible with this feature.
In my system, when the switch is turned on, it seemed to cause an expansion of the soundstage by at least 2 fold.
However, the sonics were more diffused and I preferred to leave the switch turned off (permanently).

6. Bass Switch
Bass was over boomy if I turned it on, so I left it in the "off" position (permanently).

7. Treble Switch
I left it (permanently) in the middle position cause it sounds wonderful to me.
Did not really experiment with this.

8. Volume Knob
With my current tubes, and my 88db speakers, I never have to turn the volume beyond the half-way mark.

9. Speaker Impedance (aka Epilogue)
This is a caveat to the above.
My Torii MK4 was built with 8 - 16 Ohms speaker taps.

However, despite the fact that
(a) there is a speaker impedance mismatch
(b) my speakers have cross-overs

The 8 Ohms tap sounds so good when paired with my current 4 Ohms speakers (with cross-overs!!!) that I'm seriously thinking of abandoning my original plan to use the amp with the 16 Ohms Zu Soul Superflys.

Back to top
 
 
  IP Logged
jsm71
Seasoned Member
****




Posts: 106
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #1 - 11/17/13 at 00:56:26
 
Thanks for your observations.  Everything is so dependent on other equipment, the room, and personal tastes.  I have not decided that any of the settings are permanent yet on my MK IV but I'm starting to believe I'm close.

I was particularly interested in your trials of input tubes.  I have been thinking that those will get changed next.  I also am thinking of trying to get more warmth in that area.

My speakers have pretty tight bass so I've been using the bass setting on the "more" position.  I also am using the positive feedback switch turned on.  I have the tweeter control off.  I have a similar control on my speakers and by turning it up there gives the speakers higher efficiency.  I also am using the 8 ohm tap.

The rectifier was my first change due to bumping bottles as you pointed out.  I went with Philips 5R4GYS which have a great sound and are slightly slimmer than the stock tubes.  I agree, more clearance would have been preferred.

Lots of fun and further experimentation is yet to come.  Were the GEC KT66s the first 66 tube you went with or did you try others?  I bought the Tung Sols but am open to trying others.

Scott
Back to top
 
 
  IP Logged
Lord Soth
Seasoned Member
****


I'm an American
BadAss!

Posts: 256
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #2 - 11/17/13 at 03:50:28
 
Hi Scott,

I've been using only the GEC KT66 in my Torii MK4 since the very beginning.

The reasons are due to the following below.

I learnt a very expensive lesson from tube-rolling various NOS EL34s ( on my non Decware SE EL34 amp) and 6DJ8 tubes (on my CSP2+).

For the EL34s, I started out with Mullard Xf2s ( and Other Mullard variants ) and then rolled Amperex "D" getters and finally the metal base philips EL34s.

Likewise for 6DJ8 tubes, I spent a minor fortune playing with almost all the various makes of tubes mentioned in Joe's tube lore and other exotic tubes such as Tungram, Teslas, Russian and Lorenz Stuttgart tubes.

My conclusion is that, most of the time, conventional wisdom applies when it comes to NOS tubes.
If I had just bought a pair of Pinched Waist 6922s or Metal Base EL34s in the very beginning, I would have saved myself a lot of $$$$ in the process.

So when Steve announced that KT66 tubes work better than EL34s, I decided to just get a Quad ( I got 2) of GEC Gray Glass NOS tubes and be done with the tube rolling. Smiley

For the rectifier, I also decided to tap on the experience of another tube roller.
He concluded that the Brimar 5R4 rectifier ranks alongside the famous GEC U52 rectifier.
I carried out a simple 5R4 rectifier shootout myself and found the Philips 5R4GYS to be a very good rectifier too BTW.

So some lessons I learnt from tube-rolling are:

1. Always get the "best" NOS tubes at the start
Coz it will work out to be much cheaper in the long run Wink

2. Input tube sensitivity
The Torii MK4 is very sensitive to tube rolling.
By keeping other tubes constant, a Torii MK4 owner should be able to get the required sound he likes or requires just by changing the input tube.

I think this applies to just about any other Decware amp (e.g. CSP3) due to the inherent simple design.
The stock tube configuration should be good enough for most audiophiles but Decware amps will scale upwards sonically if one uses better NOS tubes.

3. Tuberolling can still spring surprises too
This seems to be a contradiction but I've found the Siemens E288CC to work exceptionally well in my CSP2+ and CSP3.
This is despite the bashing from Joe's tube lore.
So despite my current disposition on tube-rolling ( or lack of), I would still encourage anyone to tube-roll, but only if their budget allows for it.

I also sincerely hope that other fellow Decware fans will share their tube rolling experiences. Smiley



Back to top
 
 
  IP Logged
Lord Soth
Seasoned Member
****


I'm an American
BadAss!

Posts: 256
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #3 - 11/17/13 at 14:30:15
 
Hi Scott,

My Pinched Waist Mullard PCC88 were made by the Philips Holland Heelen factory with the "Delta" factory sign.

Some of the pinched waist PCC88s are also labelled as Valvo but were supplied by the Philips Holland factory.

BTW the Pinched Waist Valvo "D" tubes do not sound as good as the Pinched Waist "Delta" tubes.

I also have some real Mullard Blackburn PCC88 and ECC88s with the Blackburn"B" factory codes. These are nice and warm but the bass seems to be not as tight as I like.

Although i got my Pinched Waist tubes from EBay, I believe that Brent Jesse Audio has the Pinched Waist tubes for sale from time to time.

Langrex UK currently has some Brimar 5r4 rectifiers for sale if you are interested.

My RCA VR tubes were purchased from vacuumtubes.net
Back to top
 
 
  IP Logged
jsm71
Seasoned Member
****




Posts: 106
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #4 - 11/17/13 at 14:33:36
 
Lord Soth,  I did a little research this morning and can't find the Mullard PCC88s.  Where do you get these?  I have good results buying from Tube Depot or Upscale Audio and they don't show these.

Scott
Back to top
 
 
  IP Logged
Lord Soth
Seasoned Member
****


I'm an American
BadAss!

Posts: 256
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #5 - 11/18/13 at 02:56:23
 
Dear Scott,

Somehow my reply to your query was posted prior to your post.

Anyway, for any other tube rollers out there,

Here's some commonly available (for now;) warm sounding alternatives to the pinched waist PCC88  (delta Holland) ranked in decreasing order

1. Amperex ( *) USA 6922 Gray Shields either "O" or "D" getters
These are sonically very close to the more famous and expensive Pinched Waist 6922s.
The $$ premium paid for an actual Pinched Waist over non Pinched Waist Amerex tube is IMHO about 10% improvement.
When a Pinched Waist 6922 is compared against a Pinched Waist PCC88, the premium paid is only for a lifting of a slight sonic veil, about 1-2%.

2. Telefunken E88CC <>
Glorious mids but bass is usually weak.
Mids are not as forward sounding  ( my personal preference ) as compared with Philips tubes
For vocals only listeners, should be good enough.

2. Mullard Blackburn (B code) 6DJ8 tubes Gray Shields
These are very warm tubes, problem is that they could be too warm (I.e. Bass could be too flabby in some audio chains)
Just a caveat, could still work wonders in your audio chain.

3. Russian 6N1Ps
Very warm but not as sonically transparent as European / American tubes
Takes ages to bloom sonically.

Other notes
For more tube warmth, I highly recommend that the NOS input tube for the Torii MK4 should be of the older "Gray Shield" variety.
New Silver Shields are brighter sounding.

Back to top
 
 
  IP Logged
jsm71
Seasoned Member
****




Posts: 106
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #6 - 11/18/13 at 14:24:27
 
If one was on a budget, couldn't upgrade all their tubes at once, or is just a cheap bastard like me, would you recommend putting your money more into NOS input tubes or better output tubes?  Where's the best bang for the buck, or are gains worth the money regardless of where spent?
Back to top
 
 
  IP Logged
tgarden
Seasoned Member
****




Posts: 399
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #7 - 11/18/13 at 17:34:19
 
Spend your money on better input tubes first. The stock ones are nothing to jump up and down about.

A decent pair of rectifiers makes a nice difference, also.

My experience with the Torii I, II, III, and III/IV conversion, anyway.

Mike in Seattle area
Back to top
 
 
  IP Logged
Lord Soth
Seasoned Member
****


I'm an American
BadAss!

Posts: 256
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #8 - 11/19/13 at 01:50:54
 
The Philips 5R4GYS Rectifier for about $50 ea from Upscale Audio is highly recommended as one of those best bang for buck upgrades.

Steve mentioned that the gain of the input tubes for the MK4 was increased over the MK3. So any investment in the input tubes will be worth it,I.e. The MK4 is very responsive to input tube rolling.
Back to top
 
 
  IP Logged
JD
Seasoned Member
****




Posts: 181
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #9 - 11/19/13 at 13:35:12
 
I second the rectifiers and input recommendations. Only rectifier I've found better than the Phillips 5r4gys are early 50's RCA 5r4gys...simply amazing and transformed my system (I have them in my ZP3, and CSP2+ as well).  Inputs are also extremely important. In my Torii 3 I've found NOS 6922 to my liking...Telefunkens and Mullards at the top. Good luck and have a blast!

JD
Back to top
 
 
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. D*ck

Posts: 7576
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #10 - 11/19/13 at 13:54:40
 
Never tried the 5R4 type in the Torii. . . saw a pair of RCA on ebay cheap and went for them. Thanks for the nudge.

I really like the old RCA 5U4 in the Torii now, so they have a lot to overcome. I've never preferred anything but the 5Y3 type in the CSP2 or CSP2+ or ZP3--the larger rectifiers just alter the sound from "neutral" too much for my taste and material.
Back to top
 
« Last Edit: 11/19/13 at 13:55:36 by Lon »  

Decware:ERR,HR-1,ZP3,CSP2+,Torii Mk III,PS Audio PWT+DS,PowerBases,PPP,AC-12 pcs, Denon DBP-A100, Denon DCD-A100,Rega RP3 +TTPSU,white belt+Exact2, VooDoo Cable:Evo,Ultra Linear, Iso-PodMapleshade:Double Heiix Plus.Samsonv2+v3 +4" platforms,Herbie's Iso-Cup
  IP Logged
JD
Seasoned Member
****




Posts: 181
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #11 - 11/19/13 at 15:27:07
 
Let me know what you think when you try them Lon.  They definitely do something (alter/enhance/change) to the music and neutral does not come to mind so they might not be to your liking...but curious to see what you think. I find the biggest change is when I listen to my fm tuner (91.9 fm out of Boston if anyone is curious) seems to add some weight, air and texture.  I should be receiving some diffusers in the next few weeks to add to my room that I also added a new credenza to as well that is holding all my equipment.  It's amazing how even the smallest change can "do" something to the music both positive and negative.  Took me 1.5 hrs the other night to figure out  what was causing the thumping noise from my ZP3 that started when I rearranged all my equipment...patience is definitely a virtue.  
JD
Back to top
 
 
  IP Logged
tgarden
Seasoned Member
****




Posts: 399
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #12 - 11/19/13 at 15:41:18
 
I have never tried the 5R4 type in the Torii either, but forum member Will has kindly lent me a pair, that I will soon audition. Looking forward to seeing what they do.

I'm with Lon on using 5Y3 types in the ZP3.  It's what Steve voiced the ZP3 with.  I've tried several 5U4 variants in the ZP3, and thought they distorted the sound.  It sounded off.

I like pre WWII RCA 5Y3's in my ZP3, but have found a 40's KenRad 5Y3GT (hanging filaments) that has adds a bit of slam/kick to the sound.

Mike
Back to top
 
« Last Edit: 11/19/13 at 15:42:34 by tgarden »  
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. D*ck

Posts: 7576
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #13 - 11/19/13 at 15:49:54
 
Patience is definitely a virtue! And the amazing blessing and curse of these machines is that you can hear everything . . .cables, power, isolation, and especially tube rolling.

I'll look forward to the rectifiers to see what they'll do in both Toriis. I have two Mk IIIs in two systems and the rooms are significantly different that one tube type may well work better than another in each system.

It's amazing to me when I get it right and mediocre recordings are very listenable and I can get immersed in the music, or the tv show or the movie. . . . . It's astonishing how Decware has changed the quality of my listening and viewing life.
Back to top
 
 

Decware:ERR,HR-1,ZP3,CSP2+,Torii Mk III,PS Audio PWT+DS,PowerBases,PPP,AC-12 pcs, Denon DBP-A100, Denon DCD-A100,Rega RP3 +TTPSU,white belt+Exact2, VooDoo Cable:Evo,Ultra Linear, Iso-PodMapleshade:Double Heiix Plus.Samsonv2+v3 +4" platforms,Herbie's Iso-Cup
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. D*ck

Posts: 7576
Re: Torii MK4 - Tube Rolling and Some Observations
Reply #14 - 11/23/13 at 23:02:26
 
Got these in. Tried them a few hours. Took them out.

Not for me. Too dry and tight and big sounding, not accurate in my system. Reminded me of the Valve Art 274B. When I can let them burn in for a day or so I will and try listening again.
Back to top
 
« Last Edit: 11/26/13 at 11:01:11 by Lon »  

Decware:ERR,HR-1,ZP3,CSP2+,Torii Mk III,PS Audio PWT+DS,PowerBases,PPP,AC-12 pcs, Denon DBP-A100, Denon DCD-A100,Rega RP3 +TTPSU,white belt+Exact2, VooDoo Cable:Evo,Ultra Linear, Iso-PodMapleshade:Double Heiix Plus.Samsonv2+v3 +4" platforms,Herbie's Iso-Cup
  IP Logged
Pages: 1 2 3 ... 5
Send Topic Print