W E L C O M E ! - - - - - - Invitation to start threads HERE

AmpDesigner333 · « **on:** 19 Feb 2010, 04:49 am »

Hey, everybody, Digital Amp Co. now has a circle!

We would like to welcome everyone and invite members to start threads in this circle.

Topics can include Class-D, our products, and general technology questions. Thanks for reading this.

-Tommy

Hank · « **Reply #1 on:** 19 Feb 2010, 12:57 pm »

Howdy and good luck going forward.

Barry_NJ · « **Reply #2 on:** 19 Feb 2010, 07:33 pm »

Congrats Tommy!

mcullinan · « **Reply #3 on:** 19 Feb 2010, 07:46 pm »

Yeah! Couldnt have happened to Nicer guy!

Emil · « **Reply #4 on:** 19 Feb 2010, 08:09 pm »

love the website

jackman · « **Reply #5 on:** 19 Feb 2010, 08:35 pm »

Very cool. Best of luck to you with the new circle. Your products look great, I hope to audition them one of these days.

watercourse · « **Reply #6 on:** 21 Feb 2010, 01:21 am »

Great start for the Year of the Tiger! Congrats and keep up the excellent work Tommy!Wilson

richidoo · « **Reply #7 on:** 23 Feb 2010, 12:46 am »

Congratulations on your own Audio Circle, Tommy. Looking forward to hearing your amp sometime.
Rich

pardales · « **Reply #8 on:** 23 Feb 2010, 01:17 am »

Good luck with the new thread.

AmpDesigner333 · « **Reply #9 on:** 24 Feb 2010, 04:20 am »

Thanks, all. Keep 'em coming (warms the heart, you know).

orientalexpress · « **Reply #10 on:** 24 Feb 2010, 06:48 am »

sweet,good start to a new year.

lapsan

mfsoa · « **Reply #11 on:** 24 Feb 2010, 01:29 pm »

Hey Tommy,

Best wishes for the new Circle!!

Just so others know, this Circle may be open to Hockey discussions as well, as Tommy is a player/fan

Just want to add that I am running XLRs from my VAC pre to my Cherry JR and experienced a big improvement in sound quality relative to using RCA-to-XLR adapters. Don't know if it's the pre doing it or the new cables or the lack of RCA-to-XLR adapters or the balanced input topology of the amp but I lovin' it!!

-Mike

gerald porzio · « **Reply #12 on:** 24 Feb 2010, 01:46 pm »

Are these amps differentially balanced?

Rick Craig · « **Reply #13 on:** 25 Feb 2010, 12:55 pm »

Quote from: AmpDesigner333 on 19 Feb 2010, 04:49 am

Hey, everybody, Digital Amp Co. now has a circle!

We would like to welcome everyone and invite members to start threads in this circle.

Topics can include Class-D, our products, and general technology questions. Thanks for reading this.

-Tommy

Did you work for Harris here in North Carolina? I designed a small speaker for demos of a class D amp developed by a few guys working there back in the 90's.

AmpDesigner333 · « **Reply #14 on:** 28 Feb 2010, 08:15 am »

Quote from: Rick Craig on 25 Feb 2010, 12:55 pm

Did you work for Harris here in North Carolina? I designed a small speaker for demos of a class D amp developed by a few guys working there back in the 90's.

I visited NC to talk to some Harris guys that were involved in the "Cool Audio" program. I had a wonderful time at a micro-brew fest that trip!
Actually, the Harris guys I worked for were in Melborne, FL. We were studying Class-D audio using their MOSFET drivers. Results indicated a healthy future for Class-D. I designed a fixed frequency system in several configurations for auto, home, and pro audio.
Good times indeed. That was previous to this project:
http://www.harris.com/view_pressrelease.asp?act=lookup&pr_id=190

AmpDesigner333 · « **Reply #15 on:** 28 Feb 2010, 08:16 am »

Quote from: gerald porzio on 24 Feb 2010, 01:46 pm

Are these amps differentially balanced?

Yes, true balanced inputs, but the output is single ended (the "minus side" is actually ground, unlike many Class-D designs). Thanks for your post.

AmpDesigner333 · « **Reply #16 on:** 3 Mar 2010, 04:54 am »

Quote from: Rick Craig on 25 Feb 2010, 12:55 pm

Did you work for Harris here in North Carolina? I designed a small speaker for demos of a class D amp developed by a few guys working there back in the 90's.

Do you remember John Fogg, George Danz, Dave Hamo, Greg Butler, or Larry King (no joke)?
How about Ivars Lumas (FL)? All Harris guys.
Hope these guys don't mind being mentioned on the Internet. If so, they can send me a PM, and I'll remove their name. All fine individuals for sure, and very good technically. Those were fun days!

targa · « **Reply #17 on:** 3 Mar 2010, 08:33 pm »

Tommy, hope all is well! i have some feedback on your Cherry Jr i can share if you want...

AmpDesigner333 · « **Reply #18 on:** 3 Mar 2010, 09:37 pm »

Quote from: targa on 3 Mar 2010, 08:33 pm

Tommy, hope all is well! i have some feedback on your Cherry Jr i can share if you want...

Sure, let's hear it!

targa · « **Reply #19 on:** 5 Mar 2010, 06:34 pm »

good fellows,

Want to share some impressions on the Cherry Jr. My system is as follows: HP TouchSmart laptop – Musiland Monitor 01 USD (USB converter) – EMM Labs DAC 6e – Placette RVC (balanced) – Cherry Jr – SP Tech Timepiece 3.0. My system is fully balanced. You can find many reviews on the EMM Labs, Placette and SP Tech. No doubts that they are completely transparent and extremely accurate. So most of what I write below relates to the ability of Cherry Jr to handle the signal it is fed and how it controls the SP Tech. Note that I also owned the Offramp Turbo 2 USB converter (w/ S4) before and had in my systems for months.

I bought the Jr directly from Tommy and had the amp for a while but not seriously listened to the amp until last 2 weeks. I have like 40-50 hours on the amp. Reason for delayed listening was that I used EMM Labs DAC directly connected to the Cherry Jr. and used the digital volume control of my laptop. Well that set up did not work. Everyone knows that if a computer volume setting is not set at 100%, the output signal looses bits (or data) and therefore “corrupted”. The result was hollow and grainy (distorted) sound. Inserting the Placette and setting the computer volume at 100% corrected all issues w/ the sound.

So how does the Cherry Jr sound in my system? I can summarize my impressions of Cherry Jr as follows: (1) flat freq response and very accurate, (2) low distortion and hence outstanding details and micro dynamics(!), (3) excellent macro dynamics, and (4) fast and exerted excellent control of SP Tech. The end result is simply musical… Some listening tests:
I listened to Beethoven Symphony 9 (Symphonie No.9 - Herbert von Karajan - Berliner Philharmoniker [2003 Hybrid SACD ]) extensively w/ the Cherry Jr. I never heard this symphony this good! Actually I barely listened to the # 9 because my older systems (e.g. Krell SACD, ARC pre and amp, Martin Logan Vantage) could not resolve the complexity and keep up with the dynamics of this piece. Now, I can hear the credible intensity and emotions of #9. I ripped the files from the CD layer of my SACD. This CD is recorded originally in 1963 and brought out in SACD in 2003. Given this early recorded time, the recording is not the best compared to modern standards. However, I can clearly hear the distinct instrument voices. The layering of the soundstage from front to back is phenomenal (i.e. resolution and micro dynamics!). The music flows easily and never sounds compressed. The recording is not the best from the perspective that – even though I can hear the instrument voices distinctively and clearly – there is not much harmonic information/ data about individual voices. The overall effect is like I am sitting in the middle or far end of the concert hall instead of in the front first few rows. For sure, I have not heard the hall in this recording so good before…

Fast forward to a more modern recording: Melody Gardot - Worrisome Heart (2007 I think on top of my head). On this recording she sings very close to the mic. I felt like she had something covered up her mouth (I exaggerated a bit here but you get the idea) while she sang when I listened through my older setups. Not so with my current setup. True that her voice is intimate due to close mic set up but for sure, she does not sound like her voice is covered up. I hear tons of harmonic data about each note she sings and the instrument voices. Listening to this recording, I get a feeling that the singer is singing to me and to me alone instead of singing to an audience. Definitely a romantic recording and purposely so.

When I listened to the above pieces of music or other through the Cherry Jr, I could easily hear the hall or space in the recordings. Of course, more so in some than other. I like musical truth and accuracy: listening to music the way the recording artists envisioned for their listeners. The emotional interpretation of that music is of course up to each listener but at least, musical content is not (or minimally) lost from artist to listener in “accurate” systems. This amp delivers on all aspects Tommy claims: ultra linear, extremely low distortion and powerful.

Well done, Tommy!