Sensation Dodd Tube Buffer

OzarkTom · « **Reply #220 on:** 5 Dec 2010, 11:56 am »

Quote from: jtsnead on 4 Dec 2010, 09:48 pm

Hey Tom,

Thanks again for the tube you sent me, I just won an auction on
a Sylvania GB5751. I will have to compare and let you know

I see someone stole one for $39.99. was that you?

jtsnead · « **Reply #221 on:** 5 Dec 2010, 03:01 pm »

No I wish, got it for $72 w/ free shipping, was the one you saw on ebay?

OzarkTom · « **Reply #222 on:** 5 Dec 2010, 03:39 pm »

Yes, that one ended on Thanksgiving day, one of the worst days to end a bid on anything. I saw the one for $72, I paid $68 with shipping for mine so you still got a good deal.

wsturner · « **Reply #223 on:** 8 Dec 2010, 04:05 pm »

The "Tube-o-phile Circle" guys were giving the Create Audio 12AX7 tube great reviews:

http://www.audiocircle.com/index.php?topic=79732.40

I went over to 32 Ohm Audio, in Portland, and picked one up. Wow!!!

If you don't feel like chasing down hard to find NOS tubes, this thing is amazing!

It blows away the following tubes:

RCA 2 mica black plate
Ge 2 mica grey plate
GE 3 mica black plate

I don't own a Sylvania gold brand 5751, so I can't compare it to that.

momini1 · « **Reply #224 on:** 8 Dec 2010, 06:29 pm »

Another new tube to consider is the Pavane offered by Grant Fidelity - $76 a pair for 12ax7. They've gotten some nice reviews. I ordered a pair last week and I'll let people know how the tube sounds.

OzarkTom · « **Reply #225 on:** 9 Dec 2010, 01:58 am »

Quote from: wsturner on 8 Dec 2010, 04:05 pm

It blows away the following tubes:

RCA 2 mica black plate
Ge 2 mica grey plate
GE 3 mica black plate

I don't own a Sylvania gold brand 5751, so I can't compare it to that.

So how does it beat all the others, especially the GE 3 mica black plate.?

wsturner · « **Reply #226 on:** 9 Dec 2010, 05:23 am »

The immediate impression I got, from the Create tube, was a significant increase in separation. Each instrument/sound was distinct from the others. It was like they had a distinct place in space. Before using the create tube, sounds would sometimes tend to "smear" together - if things got really busy. This no longer happens.

The second thing I noticed - if you can imagine it getting any better - is that the bass response got even more ballsy. With batteries, the amount of bass that the Sensation amp delivers is extraordinary. With this tube, it gets even better.

The other tubes had a nice plucky sound (acoustic guitar - for instance). The create tube is still fast, for this type of stuff, but it tends to smooth/soften things out.

Depth and "bigness" of soundstage is what I have noticed as I listen more.

It it just a beautiful, solid, tube.

OzarkTom · « **Reply #227 on:** 10 Dec 2010, 12:40 am »

That would make an interesting comparison, wsturner. The Sylvania GB has the same characteristics. Better seperation, better focus, more air around the instruments, and you hear more of the effects of the hall that the music was recordeed in than the GE's have.

Tell you what, send me your 12ax7 and I will do a serious comparison with the Sylvania GB and the Raytheon.

wsturner · « **Reply #228 on:** 10 Dec 2010, 12:55 am »

Tell you what OzarkTom. You send me the Sylvania GB, and I will send you the Create Audio 12AX7.

You just have to promise to give it back - at some point

Scott

OzarkTom · « **Reply #229 on:** 10 Dec 2010, 01:07 am »

But Scott, I need both here to compare.

Tom

Jack Caldwell · « **Reply #230 on:** 11 Dec 2010, 04:01 am »

Gentlemen, about tubes vs noise level
Have you noticed if any of the tubes you are using exhibit more/less hiss level compared to the stock tube? Any suggestions on this front?

wsturner · « **Reply #231 on:** 11 Dec 2010, 04:17 am »

Others have complained about hiss/noise - and rustling sound when adjusting the volume.

I have never had a problem with these things - regardless of which tube was used.

My speakers are not super sensitive (86db).

wsturner · « **Reply #232 on:** 19 Dec 2010, 04:53 pm »

I wasn't thinking the other night. I powered off my Sensation, using the rocker switch on the back, before putting it in Standby mode on the front.

The next morning I powered things up, and the "Protect" light stayed on - and then started blinking. I started freaking out!

I went to the Sensation owners manual:

http://www.wihifi.com/virtuemanual/Sensation_Owners_Manual.pdf

and found the following:

"Don’t freak out if Sensation goes into protection mode if you accidentally switch it off in the wrong order. Just wait about 90 seconds and restart in proper order"

I turned everything off, unplugged the power from the back, waited 91 seconds - just to be safe, and then powered everything back up like normal. This time it all worked! It seems that power needs to be completely removed for 90 seconds - for the microcontroller to reset.

Just wanted to throw this out there - in case anyone else has the same problem.

tabrink · « **Reply #233 on:** 20 Dec 2010, 03:31 am »

My well used Sylvania gold 5751 has been my reference tube for many months in my 901 but the Pavane is growing on me. They actually share many of the same attributes. Better separation, beefier low end, meaty mids and a butterscotch presentation. The Sylvania GB might be just a tad bit fuller sounding but I am so biased and used to listening to it. There really is not anything either tube does not improve. Needing to put some more hours on the Pavane and then slam the 5751 in for a comparo.
For the record I went through multiple branded 5751 and the Sylvania Gold was solidly at the top of the heap by a large margin. The Pavane is every bit as musical and I have the twin for my DAC.

momini1 · « **Reply #234 on:** 20 Dec 2010, 02:07 pm »

Here's another thumbs up for the Pavane. I rank it near the top of any tube I've tried. Great air around the instruments, deep soundstage, very direct sound - no sense of veiling between you and the music. For the price -even though you have to buy two - it's a very, very good choice.

brother love · « **Reply #235 on:** 20 Dec 2010, 04:54 pm »

Ok, I’ve had my M451 w/ Dodd tube buffer & Sonicap upgrades for 3 mos. now (ie. fully broken-in). My 2 channel rig is the tube buffer M-451, w/ Virtue Piano M1, GR Research N2x bookshelf spkrs.( w/ B & G Neo 3 planar tweeters ) & Rythmik Audio F12G servo sub. CD redbook source material is broad (anything from Black Keys & White Stripes to Miles & Mozart).

To start my tube rolling adventures beyond the stock J J 12AX7, what we would be a good start? I’d like to keep single tube costs in the $50 range.

I’m mightily tempted by the Sylvania gold brand 5751 (would the trip begin & end there? At $100 or so, it might have to for me

).

OzarkTom’s positives about the GE 3-mica black plate for an economical price is very intriguing.

The Grant Fidelity Pavane 12AX7 sounds really nice too ($83 shipped for a pr.). Anyone who wants to maybe split the pair, let me know …

rtate · « **Reply #236 on:** 21 Dec 2010, 03:29 am »

brother love , you've got pm

se-riously · « **Reply #237 on:** 21 Dec 2010, 04:39 am »

Quote from: brother love on 20 Dec 2010, 04:54 pm

Ok, I’ve had my M451 w/ Dodd tube buffer & Sonicap upgrades for 3 mos. now (ie. fully broken-in). My 2 channel rig is the tube buffer M-451, w/ Virtue Piano M1, GR Research N2x bookshelf spkrs.( w/ B & G Neo 3 planar tweeters ) & Rythmik Audio F12G servo sub. CD redbook source material is broad (anything from Black Keys & White Stripes to Miles & Mozart).

I have something similar, an M451 w/ Dodd buffer, Sylvania GB 5751 triple mica, Sonicaps/Platinum bypasses, Danny's OB-5's, and a Rythmik D15se servo. I'm really happy with the Sylvania GB 5751, and I found it easier to blend into the Rythmik over the stock JJ, and a bit of grainy edge of the highs of the JJ was taken off, but all the detail is still there.

Curious to see how you like the Pavane.

AndrewH · « **Reply #238 on:** 25 Dec 2010, 05:30 am »

I'm also interested in the Grant Fidelity Pavane 12ax7. I could split a pair.

Question - What about the 12au7? The 12au7 (note the 'u') is compatible, but with (5x?) lower gain - does that matter for our "no-gain" tube buffers? I like the idea of lower gain. My volume control is underutilized since my Sensation m901 is driving some Omega single drivers (93dB sensitive). The volume knob barely goes past 9 o'clock before I worry about the neighbors. I wouldn't mind lowering the noise floor, too. I think OzarkTom liked a 12au7.

I'm close to pulling the trigger on a pair of these Grant Fidelity Pavanes - just need your advice - which should I choose? The 12ax7 or the 12au7?

System is the m901 with cap upgrades, tube buffer, and battery supply; source is a ModWright MSB Link3 from a PC transport; speakers are Omega Super 5s, augmented by two powered sealed subs.

AndrewH · « **Reply #239 on:** 25 Dec 2010, 05:54 am »

I pulled the trigger on the 12au7s! Bought a pair of the Grant Fidelity Pavane 12au7s for $83 shipped.

I think I answered my own question - parkfly was the one who liked a RCA 6189 12AU7W JRC black plate. But OzarkTom is a proponent of the 5751 series, which have only 70% of the gain of a standard 12ax7. So I presume that the amount of gain in the tube does matter.

When I switched from my previous 88dB satellites to the 93dB Omegas, the increase in sensitivity was noticeable. But also the tonal balance seems to be lighter weight - less full in the lower midrange and upper bass. I also seem to recall the amp didn't seem to "open up" at lower volumes with the less sensitive speakers. So I'm hoping that the lower gain tube will ameliorate that. I will let you know how it turns out in a couple weeks.