[AmpDesigner333]

you do know you have the only red component out there,i would consider a new face plate for starters,even the name kinda sucks.maybe I'm too old,or old fashioned.too radical for me just looking at her.... please note i scratched this down before my first cup of Jo.no harm intended,just my early-in-the-day  comments

We are willing to paint the face black if you want!  Thanks for your post.

[AmpDesigner333]

Below, I address the list of topics from another thread, "amplifier truths and myths":

1.   Transformers: The bigger “iron”, the better, hence massive power supplies and output transfers sound best.
True that more metal saturates less easily, but the shape of the core is also important.  This is why "pancake" toroids are harder to design.  Also, once the transformer is "big enough", making it bigger doesn't add any value other than more weight.  When transformers are loaded heavily, they put out less voltage, and the power supply rails fall.  If the amp is designed to take this well, you can minimize the size without any noticeable effect on the sound.  Toroids are preferred to E cores due to stray field issues.  For output transformers, the thickness of the windings is very important.  The bottom line is that there are so many factors at play, you have to trust that the designer took everything into account.  I mentioned previously that OTL amps are preferred, but with a good output transformer design (yes, beefy), you can get good sound from tubes.

2.   Rectification: Tube rectification is better than diode, preferably with a choke in PS
Regarding the choke in the power supply, this depends on the design of the choke (core type, inductance, etc.).  Too much inductance can cause the rails to "bounce".  Also, It's too general an issue to say what's best here because every implementation can be done right or wrong.  I can't think of a solid reason to say tube rectifiers are any better than silicon.

3.   Tubes: NOS is generally better than today's Chinese, Russian, Czech and former Yugo production. It's more than just testing well.
No comment.  I'd rather leave that question to a good tube amp designer, like Roger M!

4.   Parts I - Caps : Good ol’ Sprague caps sound better than new expensive exotics
New electrolytic capacitors are very reliable, have low resistance, and are priced much more reasonably.  Exotic caps in power supplies might be a waste, and it can be a better alternative to use standard ones with good bypassing instead (ceramic, poly).  There's no such thing as "magic".

5.   Parts II - Materials: Silver is better if you can afford it. Silver transformers, wiring, etc…
Better specifications and reliability are the key.  There's no cheating physics.

6.   Design: Fewer stages the better
Too broad of a statement, but in general, this is true.  Imagine that every stage of an amplifier contributes its own distortion.  The end result is a product of the combined effects of all stages in the signal path.  However, I'd rather use three stages that have 0.01% THD than one that has 0.1%.

7.   Negative Feedback: Preferably none. Zero NFB is best
Well, once again this is about the end product and too general of a statement to be unconditionally true.  Feedback does create problems, but if done properly, it can solve more problems than it creates.  If you can make an open loop amp with no distortion, noise, or output impedance than you don't need feedback.  However, this is not technically possible.  I might venture to say that feedback design (a very involved topic) is most important to the sound of an amplifier.  Also, as output power increases, the need for error correction generally increases with it.

8.   Design II: Class A … nuff said, generally sounds better than AB, B and other variants
Class-B is not practical for audio due to crossover (neg to pos) distortion.  Class-AB is not as good as Class-A in this same respect.  The biasing of Class-AB can put it close to Class-A, but than you throw more power into the room through heat than into the speaker, especially at low volumes.  Class-H and Class-G are higher efficiency, but suffer the same problems as Class-AB.  I personally like the sound of Class-A, but it can be as much a space heater as an amplifier!  My favorite (big surprise) is Class-D.  Beware of fake class names like Class-Z and Class-T because they are really Class-D.  Class-D amps are often called "digital amplifiers", but this is a gray area as far as correct nomenclature.

9.   Construction: Hand wired is generally better than PCB
This really depends on the quality of the wiring.  Complicated designs are not "hand wirable", so I think this is a false statement. PCB layout is an art in and of itself, and if done properly is better electrically.  This wasn't the case in the 1940s.

10.   Straight wire with gain : Tone controls are generally bad, another complexity to degrade the signal from "purity"
Same as with more stages in the amp.  The less the audio goes through on the was from the source to the speaker, the better, but it's the compound effect that matters in the end.

11.  Transformer II: Transformer-coupled amps perform better than those using a cap between stages
I believe direct coupling is best (servo inputs, etc.).  Frequency response at the low end of the spectrum can be ruined by caps or transformers.  However, if designed properly the effect of good quality passive components in the signal path is nearly zero.

12.  Made in the USA: The Chinese don't care about quality of products. Made in the USA is best if you want your amp to last.
In general, yes, but I can't say if this will still be the case 20 years from now.  The Chinese are getting better at producing quality electronics every day.

Please understand that I had to limit how much time I put into this post, so I couldn't address every nuance.  The bottom line is that you can't make conclusions based on broad topics, so just listening is still the only way to know who makes a better amp.  I believe that designer experience is the most important thing, not brand name, magazine reviews, or gimmicks!  Thanks for reading this, and I invite comments!

[jman66]

Hi Tom,

How does CLDjam™ relate to the DAC4800A and Cherry amps? What can you elaborate on regarding this? Thanks.

-jim

[THE_ANSWERS]

Check this link:
http://cgi.audiogon.com/cgi-bin/auc.pl?ampstran&1219539808

Digital Amplifier Company page for this fine amp:
http://www.digitalamp.com/Cherry_amp2.htm

Also, the Cherry amp is on Google Base and Amazon (www.TrueDigitalAmp.com).  Similar to the DAC4800A amp, also on www.DigitalAmp.com.  There is a review on www.audioreview.com for the DAC4800A, but the manufacurer is listed as unknown because they don't have a way to add new manufacturers!!!  Also, there is a great review about the Cherry amp on Audiogon (see the listing for the address).

Anyway, check it out ASAP!

Just over one day left on the auction!

Thanks.

Have a great weekend...

i see the cherry unit didn't sell on audiogon or did it???????

[AmpDesigner333]

Check this link:
http://cgi.audiogon.com/cgi-bin/auc.pl?ampstran&1219539808

Digital Amplifier Company page for this fine amp:
http://www.digitalamp.com/Cherry_amp2.htm

Also, the Cherry amp is on Google Base and Amazon (www.TrueDigitalAmp.com).  Similar to the DAC4800A amp, also on www.DigitalAmp.com.  There is a review on www.audioreview.com for the DAC4800A, but the manufacurer is listed as unknown because they don't have a way to add new manufacturers!!!  Also, there is a great review about the Cherry amp on Audiogon (see the listing for the address).

Anyway, check it out ASAP!

Just over one day left on the auction!

Thanks.

Have a great weekend...

i see the cherry unit didn't sell on audiogon or did it???????

Well, we only did 3 days as a trial run and it received something like 700 page views.

Please sign up for our newsletter since we will be making a really great offer very soon (only for subscribers):
http://www.digitalamp.com/news.htm

Thanks for your post.

[THE_ANSWERS]

i am allowed to forward this pm...

"There's a great deal on a DAC4800A amp.  Less than half price.  Here's the link:
http://shop.ebay.com/?_from=R40&_trksid=m38&_nkw=DAC4800A

We are working to build them as fast as we can, but this unit is the last new one for a little while...

Thanks for taking a look."

[jman66]

There's a great deal on a DAC4800A amp.  Less than half price.  Here's the link:
http://shop.ebay.com/?_from=R40&_trksid=m38&_nkw=DAC4800A

We are working to build them as fast as we can, but this unit is the last new one for a little while...

Thanks for taking a look.

This amp doesn't look all that new, mark/smudges, et.al. on the faceplate, maybe its just a bad picture...
But, the faceplate colors differ from the DAC4800A pictures on the DAC website. Is the one for sale perhaps old stock or a refurb?

Still waiting to learn what CLDjam™ is and how it relates to the 4800A & Cherry.
Thanks.

[mcullinan]

There's a great deal on a DAC4800A amp.  Less than half price.  Here's the link:
http://shop.ebay.com/?_from=R40&_trksid=m38&_nkw=DAC4800A

We are working to build them as fast as we can, but this unit is the last new one for a little while...

Thanks for taking a look.

Huh... Answers, Did you pick up that copy about We are building them as fast as we can, or did you write that? If you are working for the company it should be in your signoff.

Everything about the DAC company is off and a little bit suspicious. Someone suggested that either you are really bad at marketing or you are not being honest. If you are building them as fast as you can... why are you not building more? Why are those two thoughts placed together? WTF! It makes no sense.

Mike

[THE_ANSWERS]

There's a great deal on a DAC4800A amp.  Less than half price.  Here's the link:
http://shop.ebay.com/?_from=R40&_trksid=m38&_nkw=DAC4800A

We are working to build them as fast as we can, but this unit is the last new one for a little while...

Thanks for taking a look.

Huh... Answers, Did you pick up that copy about We are building them as fast as we can, or did you write that? If you are working for the company it should be in your signoff.

Everything about the DAC company is off and a little bit suspicious. Someone suggested that either you are really bad at marketing or you are not being honest. If you are building them as fast as you can... why are you not building more? Why are those two thoughts placed together? WTF! It makes no sense.

Mike

im on a mailing list from them   guess you arent .   surprised this wasnt spammed to everybody      you attack is suspicious....... maybe you are a competitor or something????????

[jman66]

There's a great deal on a DAC4800A amp.  Less than half price.  Here's the link:
http://shop.ebay.com/?_from=R40&_trksid=m38&_nkw=DAC4800A

We are working to build them as fast as we can, but this unit is the last new one for a little while...

Thanks for taking a look.

Huh... Answers, Did you pick up that copy about We are building them as fast as we can, or did you write that? If you are working for the company it should be in your signoff.

Everything about the DAC company is off and a little bit suspicious. Someone suggested that either you are really bad at marketing or you are not being honest. If you are building them as fast as you can... why are you not building more? Why are those two thoughts placed together? WTF! It makes no sense.

Mike

im on a mailing list from them   guess you arent .   surprised this wasnt spammed to everybody      you attack is suspicious....... maybe you are a competitor or something????????

I subscribed to the mailing list and did not receive what you posted.

Some tidbits...
http://www.glgroup.com/Council-Member/Thomas-OBrien-19917.html
http://findarticles.com/p/articles/mi_m0EIN/is_2005_March_7/ai_n11851528

[mcullinan]

There's a great deal on a DAC4800A amp.  Less than half price.  Here's the link:
http://shop.ebay.com/?_from=R40&_trksid=m38&_nkw=DAC4800A

We are working to build them as fast as we can, but this unit is the last new one for a little while...

Thanks for taking a look.

Huh... Answers, Did you pick up that copy about We are building them as fast as we can, or did you write that? If you are working for the company it should be in your signoff.

Everything about the DAC company is off and a little bit suspicious. Someone suggested that either you are really bad at marketing or you are not being honest. If you are building them as fast as you can... why are you not building more? Why are those two thoughts placed together? WTF! It makes no sense.

Mike

im on a mailing list from them   guess you arent .   surprised this wasnt spammed to everybody      you attack is suspicious....... maybe you are a competitor or something????????

Nope. It just looks like you wrote it. Maybe put it in quotes?
Mike

[rydenfan]

Anyone actually heard one of these yet? Or know a single person who actually own one?

[THE_ANSWERS]

There's a great deal on a DAC4800A amp.  Less than half price.  Here's the link:
http://shop.ebay.com/?_from=R40&_trksid=m38&_nkw=DAC4800A

We are working to build them as fast as we can, but this unit is the last new one for a little while...

Thanks for taking a look.

Huh... Answers, Did you pick up that copy about We are building them as fast as we can, or did you write that? If you are working for the company it should be in your signoff.

Everything about the DAC company is off and a little bit suspicious. Someone suggested that either you are really bad at marketing or you are not being honest. If you are building them as fast as you can... why are you not building more? Why are those two thoughts placed together? WTF! It makes no sense.

Mike

im on a mailing list from them   guess you arent .   surprised this wasnt spammed to everybody      you attack is suspicious....... maybe you are a competitor or something????????

Nope. It just looks like you wrote it. Maybe put it in quotes?
Mike

i did that   !!!!!!

so much time of mine is wasted here    i posted on a thread about isolation platforms and realize im probably talking to someone who is gullable an cant be reached with any logic

    there is a scam at every corner

[miklorsmith]

What logic was that exactly?  Why don't you respond in that thread with your irrefutable and well-crafted thoughts?

I especially look forward to your taking on Occam with your d i g i t a l comments.  Reminds me of the old Bugs Bunny cartoons - "He don't know me very well, do he?"

Sorry for the OT, I do like the Tour idea!

[bummrush]

Seems like somebody needs cash bad,the way they being pushed over and over,sure sign to stay away,if you have hundreds of users you should be retired by now.

[THE_ANSWERS]

What logic was that exactly?  Why don't you respond in that thread with your irrefutable and well-crafted thoughts?

I especially look forward to your taking on Occam with your d i g i t a l comments.  Reminds me of the old Bugs Bunny cartoons - "He don't know me very well, do he?"

Sorry for the OT, I do like the Tour idea!

look at the other thread about the isolation platforms    i posted a new one there a few minutes ago with plenty of logic    youll see    tired of explaining it over and over    people comment about stupid stuff like sentence structure and punctuation not audio or facts     to save you the time if a cd player is designed properly it should not need a platform    see    logic

[Occam]

What logic was that exactly?  Why don't you respond in that thread with your irrefutable and well-crafted thoughts?

I especially look forward to your taking on Occam with your d i g i t a l comments.  Reminds me of the old Bugs Bunny cartoons - "He don't know me very well, do he?"

Sorry for the OT, I do like the Tour idea!

look at the other thread about the isolation platforms    i posted a new one there a few minutes ago with plenty of logic    youll see    tired of explaining it over and over    people comment about stupid stuff like sentence structure and punctuation not audio or facts     to save you the time if a cd player is designed properly it should not need a platform    see    logic

I take exception to the implication that my response to you on that thread -
http://www.audiocircle.com/index.php?topic=58880.20

in any way commented on your sentence structure or logic (if that's what you call it). My responses tried to address technical issues. I realize that you're obviously not a native English speaker, but I think it unwise to model your posts on the writings of e.e. cummings. No doubt all here would truly like to divine your actual intent, but sadly, few here are conversant with the language, logic or technology of the Zargon Legion of the Prometheus Nebula.

[Philistine]

The reason I was attracted to this forum was access to 'boutique' equipment that gives great performance and value, and the DAC amps may or may not fit very well into this categories.  The sure fire way of getting AC members interested is to get unit/units in the hands of members, either through get to togethers or tours - if the amps are good then sales will follow very quickly!  At the moment all that's being generated are posts going nowhere, I would like to see posts based on feedback reviews.

I'm not trying to be negative, on the contrary - if the product is good then I would like to know and, as I stated, sales will follow.

[AmpDesigner333]

Hi Tom,

How does CLDjam™ relate to the DAC4800A and Cherry amps? What can you elaborate on regarding this? Thanks.

-jim

Jim,

Sorry for the delay.  CLDjam is a patented modulation technique used in our amplifiers.  This technique allows maximum use of the power rails for close-to-limit output with high stability.  The modulator is a high order feedback design that relies on a solid high-current inner loop.  I can tell you that we tried several general topologies over more than a decade to narrow it down to the CLDjam process.  I can also tell you that this process needs careful implementation to live up to its potential, so our design is not only about the technique; it's about the practical issues as well.  We surround the modulator with a strong power supply, clean front end circuit design, and carefully selected components to achieve good bench measurements and great sound.  Over the years, this design has been "tweaked" for sound where it actually made the bench measurements not come out as good (even though they are still top notch).  We found that test equipment favors some effects that ears do not, but this is nothing new to many audio enthusiasts.  Hope that explains CLDjam for you.  Please don't hesitate to reply with more questions.  Thanks for your kind post and patience in answering it.

Best Regards,
Tommy / DAC

[AmpDesigner333]

The reason I was attracted to this forum was access to 'boutique' equipment that gives great performance and value, and the DAC amps may or may not fit very well into this categories.  The sure fire way of getting AC members interested is to get unit/units in the hands of members, either through get to togethers or tours - if the amps are good then sales will follow very quickly!  At the moment all that's being generated are posts going nowhere, I would like to see posts based on feedback reviews.

I'm not trying to be negative, on the contrary - if the product is good then I would like to know and, as I stated, sales will follow.

Yes!  That's exactly what we're trying to do, but this will take some time.  We are planning to attend a "rave" in October, and we are also offering demos to AC members on a limited basis.  DAC is a bootstrap operation, so units are built as they are sold.  We would have more units on hand if we had a pile of cash to fund higher volume production, but this is not currently the case (we hope someday it will be!).  We also offer deals to our newsletter subscribers (see http://www.digitalamp.com/news.htm) as units become available.

We AVOID a few things (mentioned in previous posts) so we can offer the best value possible.  We don't sell through dealers --- they take pretty high margins.  We don't attend trade shows --- these are very expensive.  We don't pay for advertising --- this is a huge expense for a small company.  We feel the benefits of skipping these three major expenses is very beneficial to our customers.  Our products are special; not the same old thing you see in your friends listening rooms.  We also had a massive development effort over the years to create these products, and we are stretching that expense well into the future.

So, if you're looking for customer reviews, look here:
http://www.digitalamp.com/DAC_REVIEWS.htm

... and there's one on Audiogon for Cherry:
http://forum.audiogon.com/cgi-bin/frr.pl?ramps&1216594678&read&3&4&

... and there's one on Audiogon for DAC4800A:
http://forum.audiogon.com/cgi-bin/frr.pl?ramps&1179282474&read&3&4&

...and for both DAC4800A and Cherry here (Amazon, all 5-stars!):
http://www.truedigitalamp.com/

We have some reviews that have not been added to our web site yet.  Life's busy, you know.

Well, thanks so much for your kind post!