[wushuliu]

I've had the opportunity to hear a demo Super D amp board  (120/60) on the mids/highs in my system yesterday and all I can say is it's better than the previous versions. It has all the tonal characteristics of the Class D board but with more bloom and a deeper soundstage. I'm hearing more venue "spatial cues" now and the presentation is indeed more three dimensional (and more tube-like in that respect). I got about 5 hours listening in late last night of classical, jazz, female vocals, chamber and symphonic and alt rock music and these characteristics kept coming forward.

Aw, man. Now I gotta shell out more for the Supers! 

At least I don't have to worry about the PS and toroid, and can just get the amp itself.

[srb]

Tom has already done the hard part.  He sucessfully reproduced a version of the IRC eval board, sourced the production of the PCB, parts and assembly, and was able to package and sell kits at a reasonable price.  And now he's redesigned for a new series, partially fueled by customer feedback.
 
So, my admiration for a job well done.  My hope is that a few of my suggestions will be entertained, so that his hard work can be presented to, and clearly and completely understood by, eager excited hobbyists.
 
I expressed interest not too long after this thread started, but I am not in a great hurry.  I have exchanged a few emails with Tom and a few with AC members, and my confusion has been lessened, but not totally eliminated.
 
I am still working on the chassis end of it, so I look forward to finding out additional details, pricing and comments on the new Super D from the first customers.
 
Steve 

[jtwrace]

I am still working on the chassis end of it,
Steve

Steve
If the chassis is an issue, I'll be able to help with my chassis...

[JDUBS]

jtwrace, any news (pics?) on the enclosures?

-Jim

Awesome.  Thank you, sir!   

-Jim

[dewardh]

the typos that pop up on the site. I've shot emails as a heads up

Me too, back in mid-February . . . like the power supply voltage requirement for the 120x2 being incorrect, and the pictures no longer matching what's delivered.

The web site, and documentation in general, does not seem to be a priority.  Or even a serious consideration.  Written questions often go unanswered, and sometimes the information given out verbally (at least as it's been reported here) is clearly incorrect (or misreported), without any correction from classDaudio.  It's unfortunate, because it's a good product that suffers substantially from poor presentation and support.

[dewardh]

Aw, man. Now I gotta shell out more for the Supers! 

Why?  Apart from a balanced input buffer what's changed?  Perhaps if your amps are not properly matched to your source then changing the input (particularly the input impedance) might help . . . but if it's already properly matched then adding a balanced-to-unbalanced converter (the input to the IRS2092 is unbalanced by design) offers no improvement.  And if your source does not have balanced outputs then the amp input is not balanced either (even if it is capable of taking a balanced signal) . . . you tie one signal lead to ground.

One other thing that might change (although it's not been mentioned so far) is that the original boards are inverting amps . . . so it is important to watch polarity when mixing with the more common non-inverting amps behind an active crossover.  You have to wire the speakers "backward" with a classDaudio board to get forward cone motion with a positive going signal.  That may be corrected with the new input buffer . . .

[mjosef]

One other thing that might change (although it's not been mentioned so far) is that the original boards are inverting amps . . . so it is important to watch polarity when mixing with the more common non-inverting amps behind an active crossover.  You have to wire the speakers "backward" with a classDaudio board to get forward cone motion with a positive going signal.

What the hell...so you mean I had two opposing phase in my biamp set up while auditioning recently? Mhnnn...And why is this information not revealed on the spec sheet on the website?

[hasekisgod]

I agree with all these comments. From what I've gathered from Tom lately, he's developed the Super D series to address many of the issues many of us have had regarding gain matching with adjustable gain pots, impedance matching, better heat dissipation to drive lower impedance loads, balanced inputs and board plug-ins for remote power switches and LED's to eliminate soldering on such a small board.

He's told me he is working on getting the website up to date and provding a newletter to describe all the changes he has made in his line. Again from what he's told me, Wushuliu's comments hold true. He's been overloaded with business since this amp news has hit Audiorcicle and part of that was my fault. I didn't realize this thing would skyrocket like it has.

I've suggest to TOm that he make an announcement of his new product line in Industry News where he can hopefully answer questions as well.

I think he just has too much on his plate right now.

But onto the main reason why I'm posting. I've had the opportunity to hear a demo Super D amp board  (120/60) on the mids/highs in my system yesterday and all I can say is it's better than the previous versions. It has all the tonal characteristics of the Class D board but with more bloom and a deeper soundstage. I'm hearing more venue "spatial cues" now and the presentation is indeed more three dimensional (and more tube-like in that respect). I got about 5 hours listening in late last night of classical, jazz, female vocals, chamber and symphonic and alt rock music and these characteristics kept coming forward.

So in summation, I think in Tom's defense, he is working toward a really high quality product at a ridiculuously low price so I think we have to cut him some slack here. He's obviously suffering from the growing pains that are the result of his fine work.

More later,

steve k

What tom told me was they sounded the same but have more features. The output stage is the same. And with the mods people are doing, doesnt have an affect on the sound if it did he would of did it in the first place. He is getting alot of boards that are in need for repair that people tired to mod them and messed them up. It set him back because of it. I feel if you mod it he should not be repairing it for free.

From Tom,

Yes, I see lots of people are trying to mod these amps… first, if the mods would help, I would build them that way in the beginning. The reason I am so backed up with my work now is several people have tried to modify the amp and ruined them. These are very hard to work on and change parts without damaging them. I have several here that need to be repaired. These are some of the finest sounding amps available, so really no need to try to change them. I understand people are trying to improve them, but allot of the things they are trying to do have no effect on sound quality at all.

Tom

[lo_tse]

Dave,

I really like your chassis!  I went to the Par-metal.com site and found that the same chassis can be ordered with a conductive coating (Alodine).  I am thinking it may be the one that I want.  By the way, how did you make all the holes at the rear panel to accomodate the RCA plugs and the speakers terminals?  Did you use a hoel saw, a drill press or???

Thanks!

Allan





Toob,
I used a file to remove the front panel punch-out markings, then proceeded with a scotch brite pad to improve the brushed finish. I think It looks pretty good. An LED would have enhanced the front appearance. I like it, but am not hyper- picky about gear aesthetics.

If you have doubts, perhaps your question is already answered and you should go with the more expensive case.  Highly subjective.

Oh yes, I'm glad I bought it and would buy another. You may hate it....Such is the way of things.
Dave
[/quote]

[steve k]

What tom told me was they sounded the same but have more features. The output stage is the same. And with the mods people are doing, doesnt have an affect on the sound if it did he would of did it in the first place. He is getting alot of boards that are in need for repair that people tired to mod them and messed them up. It set him back because of it. I feel if you mod it he should not be repairing it for free.

Tom told me the sound was the same but the soundstage and imaging was different in his system. He asked me my opinion and I agree. I liken the imaging much more to the 3D presentation of a tube amp vs. the flatter, wider soundstaging of his previous amps. Niteshade made reference to these differences in this post: http://www.audiocircle.com/index.php?topic=79188.0. I prefer the new board better in my system. YMMV.

I agree with you about Tom repairing people's screwups. I'm sure he's trying to keep everybody happy but that can be difficult at times particularly with us crazy audiophiles. 
steve

[Steidl Guitars]

The lack of clarity about offerings is an issue that seems easily fixed. 

No matter, Tom is a terrific guy.  He was remarkably helpful, friendly, and courteous to me when I needed his help to assemble the amp.  A real stand-up human. 

[toobwacky]

Dave,

I really like your chassis!  I went to the Par-metal.com site and found that the same chassis can be ordered with a conductive coating (Alodine).  I am thinking it may be the one that I want.  By the way, how did you make all the holes at the rear panel to accomodate the RCA plugs and the speakers terminals?  Did you use a hoel saw, a drill press or???

Thanks!

Allan

FWIW, I'm planning on using 1/4 phone jacks for the line ins and speakers outs and just a 2 wire power line with a strain relief.  I've chosen these because they can all be easily and neatly drilled with no other metal working tools required.

Easy peasy.   

[srb]

"Step" drill bits make very nice holes in sheet metal, particularly soft aluminum.  You just have to be careful not to inadvertantly keep going to the next step size.  I usually use a piece of electrical tape on the next step of the bit to mark the size limit.
 
Obviously if your panels are thicker than 3/16" (or whatever the depth of each step on your bit) these won't work for that application.
 
Steve

[hasekisgod]

Tom told me the sound was the same but the soundstage and imaging was different in his system. He asked me my opinion and I agree. I liken the imaging much more to the 3D presentation of a tube amp vs. the flatter, wider soundstaging of his previous amps. Niteshade made reference to these differences in this post: http://www.audiocircle.com/index.php?topic=79188.0. I prefer the new board better in my system. YMMV.

I agree with you about Tom repairing people's screwups. I'm sure he's trying to keep everybody happy but that can be difficult at times particularly with us crazy audiophiles. 
steve

steve what power did you get on the super? i have 3 sets of the 250 watts ch @ 8 ohms. there is no doubt i will be gettin a few of the supers. i can use the ones i have now on the bass and subs.

update: oh i think you said 120/60 in power right?

[Occam]

FWIW, I'm planning on using 1/4 phone jacks for the line ins and speakers outs and just a 2 wire power line with a strain relief.  I've chosen these because they can all be easily and neatly drilled with no other metal working tools required.

Easy peasy.   

The desire to avoid non circular hole drilling shouldn't compromise safety. As SRB points out, a step drill makes the effort easy -


The above is a standard electricians step drill for making holes to accommodate either a 1/2 or 3/4" NPT doodad (7/8 & 1 1/8" actual holes).

A wonderful doodad is a cable gland -


The above is a 3/4" npt cable gland that will secure a cable up to .72 inches in diameter. Plenty enough room for a 3 wire grounded powercord. Unless you're building to Class II appliance insulation standards (you can't), you really should use a safety grounded power cord so you can safety ground the metallic chassis.

FWIW,
Paul

[steve k]

steve what power did you get on the super?

The 60w 8 ohm / 120 w 4 ohm.

[toobwacky]

I went to the Par-metal.com site and found that the same chassis can be ordered with a conductive coating (Alodine).

I'm wondering if the Par-Metal cases with the Alodine coating will oxidize... Does anyone know?

Maybe I should clear coat it with some sort of clear spray.  Any suggestions?

[toobwacky]

A wonderful doodad is a cable gland -


The above is a 3/4" npt cable gland that will secure a cable up to .72 inches in diameter. Plenty enough room for a 3 wire grounded powercord. Unless you're building to Class II appliance insulation standards (you can't), you really should use a safety grounded power cord so you can safety ground the metallic chassis.

FWIW,
Paul

Good tip, thanks! 

Now if I can only find one in the little cow-town I live in.   

[JDUBS]

Good tip, thanks! 

Now if I can only find one in the little cow-town I live in.   

Or for another round hole installation, this one allowing for removable power cords, the Neutrik Powercon:

http://www.neutrik.com/fl/en/audio/210_t2_1141147856/NAC3MPA-1_detail.aspx

Only pain would be having to had a Powercon connector to your power cord.

-Jim

[nodiak]

srb, you should contact Tom to see if he's interested in trading an amp for help with his web page. I've made deals like this with small/new companies from both sides of the issue. It's usually easy to come to an agreement that satisfies both people. "Just a thought".
Don