Texas Digital Amp Comparison

DanWiggins · « **Reply #20 on:** 14 Mar 2006, 10:24 pm »

StevenACNJ,

No noise problems at all - you have a great preamp, with a nice low output impedance. The problem is only if you have a VERY high output impedance, or leave the inputs floating. With any decent preamp, you won't have any noise problems.

Kevin,

Spot-on! They are normally dead quiet, if used properly. Using them improperly - like most audio gear - is a definite problem!

Samplesj,

That's how I hook mine up. We do everything single-ended here, so I just run a shorting wire from the - input to the input ground. That takes care of any potential issues! We actually do it at the board - just a small zero-Ohm jumper from the - input to the input ground. And we put a 12K resistor from the + input to the input ground. No more problems.

Do I need that 12K resistor? Not in my system, but we do loan them out, so we do make sure that we can co-exist with a lot of other cabling/connection systems.

Dan Wiggins
Adire Audio®

Stempy · « **Reply #21 on:** 15 Mar 2006, 12:37 am »

Just wanted to 2nd how quiet Kevin's amp is. I have just completed a week long demo and was startled by how quiet the amp was running my ZU Druid(s). I normally use Red Wine Modded Teac's or Clari-ti's, with the gain on both tweaked down a hair. Kevin's amp was equally black in noise and background. The amp possesses a very well defined soundstage and a spooky 3 dimensional palpable quality

The amps ability to handle impedence of most any speaker is a strength that can' be taken likely. Unlike the tripath's which are more sensitive to load matching.

So Vinnie if your reading this don't get pissed, my first comments and their not about one of the great Red Wine products I own. Chalk it up to the "Fickled Finger of Fate"

Dr. Krull · « **Reply #22 on:** 15 Mar 2006, 01:18 am »

Quote from: Dr. Krull

Quote from: DanWiggins
my preferred solution would be for Hypex to make the input impedance 10K (best)

Isn't that how it used to be?

-Krull

Perhaps Mr. Wiggins and Kevin were not aware that the original UcD modules were shipped with 10k ohm input impedance. I can only assume that Hypex "caved in" under customer pressure to raise the input Z to 100k ohms. Unfortunately, many customers do not realize the trade offs involved in making such a design change.

-Krull

Kevin Haskins · « **Reply #23 on:** 15 Mar 2006, 01:19 am »

Quote from: Stempy

Just wanted to 2nd how quiet Kevin's amp is. I have just completed a week long demo and was startled by how quiet the amp was running my ZU Druid(s). I normally use Red Wine Modded Teac's or Clari-ti's, with the gain on both tweaked down a hair. Kevin's amp was equally black in noise and background. The amp possesses a very well defined soundstage and a spooky 3 dimensional palpable quality

The amps ability to handle impedence of most any speaker is a strength that can' be taken likely. Unlike the trip ...

Thanks Stempy..... the funny thing is that your demo amp came directly from the Texas event. It is the same amplifier that got overwhelmingly negative comments.

art · « **Reply #24 on:** 15 Mar 2006, 01:39 am »

What are you guys beating Kevin up for? I have built amps with both versions of Hypex modules..............10k & 100K, and neither version have any noise issues. Gimme a break.

Pat

kfr01 · « **Reply #25 on:** 15 Mar 2006, 02:38 am »

Quote from: art

What are you guys beating Kevin up for? I have built amps with both versions of Hypex modules..............10k & 100K, and neither version have any noise issues. Gimme a break.

Pat

No one here was beating Kevin up. This thread was a response to the Texas Digital Amp Comparison event.

Mr. Wiggins had posited the impedence issue as a possible cause of the reports of noise.

arthurs · « **Reply #26 on:** 15 Mar 2006, 03:09 am »

I thought the posts were rather supportive of Kevin....lighten up Francis....

Kevin Haskins · « **Reply #27 on:** 15 Mar 2006, 05:33 pm »

Quote from: Dr. Krull

Quote from: Dr. Krull
Quote from: DanWiggins
my preferred solution would be for Hypex to make the input impedance 10K (best)

Isn't that how it used to be?

-Krull

Perhaps Mr. Wiggins and Kevin were not aware that the original UcD modules were shipped with 10k ohm input impedance. I can only assume that Hypex "caved in" under customer pressure to raise the input Z to 100k ohms. Unfortunately, many customers do not realize the trade offs involved in making such a design change.

-Krull

Yes... I've used both and neither have noise problems. I disagree with Dan in the need to do anything about it. It is an advantage for most of my customers because a very large number of them are using tube preamps. These are some of the quietest (all versions) amps I've ever worked with and the only way to get noise out of them is to hook them up incorrectly.

DanWiggins · « **Reply #28 on:** 15 Mar 2006, 07:13 pm »

Dr. Krull,

Yeah, I remember that's how it used to be, and I cautioned Hypex against doing it, but I was just one of many voice in the wilderness!

Arthurs,

My name is psycho - Anyone calls me Francis, and I'll kill them!

Kevin,

That's right, you have all those hollow-state customers...

For everyone,

In all reality, it's only a problem if you leave one of the inputs floating! If you ground/short the unused inputs, you don't have noise issues. None. My solution is only to make an already nearly-idiot-proof product even more idiot-resistant, but making it so that the end-user can't forget to ground/short the inputs... It does play havoc for some people with high output impedance line stages, but hey, that's not MY concern...

Dan Wiggins
Adire Audio®

Kevin Haskins · « **Reply #29 on:** 15 Mar 2006, 07:49 pm »

Quote from: DanWiggins

Kevin,

That's right, you have all those hollow-state customers...

Hey... at least I'm not smoking Hemp!

RAW · « **Reply #30 on:** 15 Mar 2006, 07:57 pm »

darwin · « **Reply #31 on:** 16 Mar 2006, 02:52 pm »

Quote from: Kevin Haskins

For those who have read through the shoot-out Danny conducted our amp got simply thrashed in the subjective evaluation. Since our experience has been decidedly positive with the Hypex UCD modules we where more than a little surprised...

Well, that solves that mystery. I read the results of the comparisons and was totally puzzled as my experience with the amp(s) I purchased from you have been completely different. I have mine hooked up through the balanced inputs to the XLR outputs of an Outlaw 990 pre/pro and the results have been stellar - total dead black silence and all the detail and punch I could hope for - however, I think these amps are deserving of a better preamp. My Maggies love these amps and if my Maggies are happy, I'm happy. Although, three of my Maggies are now feeling neglected because they don't have their amp yet.

I hope the review hasn't hurt you any. I wouldn't hesitate to buy these amps again and I'll certainly continue to recommend them to others.

Kevin Haskins · « **Reply #32 on:** 16 Mar 2006, 05:26 pm »

Quote from: darwin

Well, that solves that mystery. I read the results of the comparisons and was totally puzzled as my experience with the amp(s) I purchased from you have been completely different. I have mine hooked up through the balanced inputs to the XLR outputs of an Outlaw 990 pre/pro and the results have been stellar - total dead black silence and all the detail and punch I could hope for - however, I think these amps are deserving of a better preamp. My Maggies love these amps and if my Maggies are happy, I'm happy. ...

The three banger should be making its way out the door soon. I'm waiting on a Hypex order that has been stuck in customs for THREE WEEKS for just the input cables for your amp.

In terms of the review it was a real stunner. Hard to swallow considering their noise performance is one of their real strengths. I don't think I've ever worked with an amplifier that has a lower noise floor.

I'm putting the brakes on the finished amps for the moment until I can gauge the fallout from this thing.

Voodoo Rufus · « **Reply #33 on:** 16 Mar 2006, 07:26 pm »

I had a thought. Since the other Hypex based products in the comparison fared well, and are similar to your amps, perhaps you should just move forward as planned?

How publicized was this event?

kfr01 · « **Reply #34 on:** 16 Mar 2006, 07:41 pm »

Quote from: Kevin Haskins

I'm putting the brakes on the finished amps for the moment until I can gauge the fallout from this thing.

Kevin:

It seems to me that a good technical review with lots of quality measurements would patch things up quickly.

I know your amplifier has zero audible noise when used correctly. Everyone who has heard it used correctly knows the same.

However, I'm just some guy with a pair of ears. Have a known E.E. put the thing through its paces and post some graphs, Stereophile-esque.

Your customers are practical, Kevin. A little proactivity here could provide a nice counter-point to the Texas thing.

Best wishes!

Kevin Haskins · « **Reply #35 on:** 16 Mar 2006, 09:28 pm »

Quote from: Voodoo Rufus

I had a thought. Since the other Hypex based products in the comparison fared well, and are similar to your amps, perhaps you should just move forward as planned?

How publicized was this event?

It is more than that... selling a finished product is a headache. If I just sell the parts all I do is take orders and ship product. I don't have to play this game of politics and damage control. I don't have to smooch some reviewers arse and I don't have any of the liability concerns that go with selling a finished amplifier.

Dr. Krull · « **Reply #36 on:** 16 Mar 2006, 09:35 pm »

There are literally hundreds of people who post frequently on the diyAudio site that have build Hypex based amplifiers and every comment I've read has been extremely positive. The only conclusions I can draw from the amplifier shootout event is that the results are invalid. I say that having listened to both the Sonic Impact and UcD amplifiers in my own system.

-Krull

samplesj · « **Reply #37 on:** 16 Mar 2006, 09:52 pm »

Actually two UcD were in the top three for most preferred at the listening test. That is part of what struck so many of us as odd. Gary Dodd's submission wasn't a tube amp, but instead was UcD modules. The Superphon amp was also based on UcD modules.

dawaro · « **Reply #38 on:** 17 Mar 2006, 01:34 am »

Kevin,

Have you given any thought to sending the amp to The Audio Critic for a review. His reviews tend to be very straight forward.

CornellAlum · « **Reply #39 on:** 17 Mar 2006, 02:18 am »

Quote from: Kevin Haskins

Quote from: Voodoo Rufus
I had a thought. Since the other Hypex based products in the comparison fared well, and are similar to your amps, perhaps you should just move forward as planned?

How publicized was this event?

It is more than that... selling a finished product is a headache. If I just sell the parts all I do is take orders and ship product. I don't have to play this game of politics and damage control. I don't have to smooch some reviewers arse and I don't have any of the liability concerns that go with selling a finished amplifier.

Screw the reviewers, if your product is good enough and has a decent value proposition, then it will stand on it's own. I think the kissing arse comment applies to every industry and every product out there. As anyone who is in some segment of sales, and aren't we all when it comes down to it, kissing arse is part of the game.