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Would that be similar to using 0C3 or 0D3 VR tubes for the power tubes on a UFO25?

I find that to be the case with my SEWE300B and I think of it as "natural compression"--more gain coming into the amp with the gain of the amp turned down, tends to damp treble energy as if the signal were "compressed" by a compression device.

Every room and every set of ears is different. I wrote it like I hear it and understand it. I'm not an engineer and I don't have an affinity for engineering. So. . . that's how and what I hear where I am upstairs here in my expanded 1918 cabin home.

Same here, Lon. Just sharing what I hear and trying to understand my audio experience more.

Thanks, James. That does help. Once I think about it from the tube perspective it makes a lot more sense.

Loving the sound coming from my system today, regardless of!

I am presently working on the DynaGrid Jr.  It is the same unit without the adjustable voltage drop.  So far it's going well, mimicking the 5u4G voltage drop pretty closely on everything from the ZP3, to a TORII JRv2 to a Sarah 300B, which I had originally determined was impossible so I'm pretty happy about that.  The sound is exactly the same assuming you have the adjustable one adjusted to match.  This unit looks identical, but would be half the price and take far less time to make.  

Yes, it works on all Decware amplifiers, and should work on all components that use a 5U4G rectifier, but I am still in the process of testing it.

Here is a list of the rectifier tubes that the Dynagrid could replace:









The exception is the 5V3A and GZ33.  While the Dynagrid can handle the current and higher voltages likely to be found in amps that use these rectifiers, I don't plan to make the voltage meter on the DynaGrid that go that high.

This is an impressive set of rectifiers and its nice to see, at the very least, there has been a lot of thought about how the DGR works across multiple rectifiers.

I wonder also how it might fit within the chain in terms of sound quality. Since it seems it will work on a phono/pre/dac/amp or wherever there is a 5U4 type tube, what might be the advantages/disadvantages or sound qualities be when you move it around to different components. I.e. does it sounds the same run from a preamp and a power amp? How does it sound if you run two? Or, if you have 5U4 rectifiers on all your components, what if you had a DGR on all of them?

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The answer involves testing links in the chain to find the weakest one.  The weakest link in the chain sets the fidelity.  If you eliminate the weakest link in the chain, you will create one or two more albeit less compromised than the first and so on it goes.

If I design or redesign any more amplifiers, this is likely to just be part of it.  I can only imagine never having to hear about blown or arcing rectifier tubes again, or having to educate people that they need to be changed regularly in higher power applications.  While an 845 tube is expensive, you'll never need to replace it.

GS, if I didn’t live in the desert, where tube heat is a consideration, I would wholeheartedly second your request to Steve.

Randy

Hey all!

...just popping in to check out the DGR thread. I just had told myself I was too tired to write a bunch about this at the moment...Iguess I couldn't help it! oh well, here it is

I haave been able to give them a listen a couple times now, and I really like what is going on with this project. My initial introduction was to the DGR Sr. on the digital rig. The smoothness was eerily impactful... when I noticed the blackness in the background and general ease of presentation of an after dark listening session during the daytime with the entire building buzzing with noise... I made note of it. But, that was the digital rig... if the digital rig sounds that good... {at this point, please envision a brilliant shaft of light shing through the Decware listening room window falling perfectly on Steve's modest turntable on the other side of the room...} [Thanks:)]

BUT WHAT WOULD IT SOUND LIKE OVER THERE!!!!

I love a good surprise, so I tried not to pry too much after I saw several prototypes in and out of the room and adjustments being made... a tinker here... a tinker there...

Two Tuesdays ago my patience paid of and listening nite was a surprise introduction to the DGR Jr. onn the analog rig... I was super stoked!! Our freind Ian had brought in some real nice cuts from his collection and it made these records really vibe. Unfortunately, there was not much known (to me) material played that night, so I didnt get a real good feel for it initially, but I noticed some things I thought I might really like. So this week I came loaded for bear and really threw as much of my referance cuts at it as I could and it was very rewarding.

I meant to chime in on this a little sooner... better late than never, eh!

Cheers

Awesome to hear Steve! Looking forward to seeing this come through. I’d be super curious to hear ultimately how different the DynaGrid sounds vs. my STL-MK104s (Space Tech Labs’ entry level “Super Rectifier”).

After a brief foray with Mercury Vapor 866a tubes, now settled in with Xenon tubes 3b22 and 3b28 on each and plugged into the Torii MK V.

Can’t wait to see this one released!

Do we have an indication of the price of the full and Jr versions yet?

Thanks

... just reporting back to the thread now that I have had time to be able to hear some of my reference albums on the DGRJr. I have been able to sneak in a few sides here and there over the last couple weeks and have been very pleased (as usual).I now have had a chance to hear my current solo acoustic instrumental reference album side A of Keith Jarrett's Koln concert (Japanese Original Pressing, PA-6053-54, IIRC), along with side A of Art Pepper meets the Rhythm Section (180g, CR00491) to round things out for acoustic group recordings.

It took me at least a half hour to recover from the Keith Jarrett. It shook me. I may never be the same, actually, but at least I can focus now. Between the very real feeling of the size of the venue, which I actually have no point of reference for other than the tone of the record, and impact of the of the more punctual notes the timing, soundstage, and depth of field was completely locked in. Given a blindfold, I would have a problem betting money on if it was a live performance or not. SO stable you could almost walk around the piano.

Just looking back on it I am still a bit worked up.

That's all I have for the moment... carry on.


Modifying the post just to add... that as far as the technical aspects of the DGR are concerned I am not as intimately familiar with these things as say, for example, Steve, but from the user end experience there is nothing "Jr" about it. This is an amazing addition to already amazing gear. I am really excited for it's launch so I can hear about all of the customer experiences with it.

I have heard the jr on the analog side of the room, and the senior on the digital side of the room Both running through the 300b on their respective setups. IIRC.

I try to understand, and you know I am rather thick  [smiley=icqlite21.png]
It seems that "sag" is beneficial in tubes amp because it brings "wanted" lag and distorsion, the kind valves officionados love so much. Hard to understand but let it be.
Now this device would cancel this sag, am I right ? To me it sounds good but to the majority of tubes fanatics, it should not. I don't quite catch it.

The chassis have arrived and look great.  They are stainless steel with our standard black powder coated finish.  I hope to put the first production model together this week.  

We have been listening to the DynaGrid Jr, exclusively for the past several weeks on the Sarah 300B and the UFO25.  I have been throwing New Old Stock 5U4's, the Decware 5U4's and some $400 Chinese 274B's by Linlai and PsVane at these amps for some time.  They all sound good.  I tend to favor the 274B in the Sarah, which is what we were listening to tonight.

I frequently use the Dynagrid and then go back to rectifier tubes in a spontaneous cycle.  We have had several concurrent Tuesday night sessions using the Dynagrid so tonight I removed it and re-installed the ACME 274B without telling anyone.  This is where it gets interesting.

The night started off sounding OK but not great.  I looked around and everyone was more or less digging it, so I blamed my cold for the sound.  It was good, but not one of those 'amazing' nights that are common around here.

As the night progressed we put the third album on and the band was fairly hard and complex.  It sounded a little dry and small and I thought this is going to be one of those LP's that doesn't do a lot for me.  The sound was off.  It needed help.  This kind of music doesn't work when it gets lean or dry or flattened or pinched or dehydrated.  Always blamed the recording since everything else sounded better... (foreshadowing)

It hit me that this would be a perfect LP to test the DynaGrid on and see if anyone can hear the difference.  So I cued the stylus off the record, and turned off the Sarah amp, pull the hot rectifier tube out with a cloth, inserted the DynaGrid, turned on the amplifier and then the Dynagrid.  It was basically almost a hot swap with the volume on the amplifier at 2:00.

I put the needle back down in the same place on the track and the difference was so obvious I didn't even have to ask.  It literally fixed the record.  Of the three we listened to, this one was definitely going to be the worse sounding one, and it went to the best sounding one.  I was surprised, as was everyone, that the difference was that big.  

With the original adjustable DynaGrid it was easy to attribute the improvement in sound to your adjustment of the knob and subsequent voltage drop.  With the DynaGrid Jr. there is no adjustment.  It just mimics the stock voltage drop of the rectifier tube.  So while increasing the voltage drop with the original model may add some sweetness, this time there was nothing but the design itself, a far more honest AB test.  

Anyway, this is about the third or fourth time I've made myself less than thrilled with the sound of the amplifier when running a stock rectifier tube,  even a $400 one.  Proof that everything is relative and you can't un hear things.

The best way I can describe the difference in sound between the $400 ACME 274B in a Sarah, which was one of the better sounding so far, and a DynaGrid Jr. in the Sarah, is like going from LP to a master tape.  The extra density, body, space, ease, dynamics, realism clearly demonstrates that rectifiers are a weak link in the chain.

If I build any more amplifiers, this will become the standard way it is rectified.  There isn't anything that is going to sound better, and the tube will probably last as long as the amplifier so you have double the juicy benefits of a tube rectifier without having to tube roll, or deal with arcing rectifier tubes.

I'll keep you posted.  Sarah has a list of the first 10 so we should be able to get those out this winter.

Steve  :)