Open discussion as per Chris’s request.

[Victor]

…what would you think, if for starters, you started a new thread where you just tell us all about yourself? We're always interested in members telling us about them, where they're from, what their interests are, what their current A/V setup consists of, what they've owned in the past, etc. If you have a past in the A/V industry, perhaps you could share with us what your education is, how you ended up there, the kind of work you've done, etc.

I think that kind of stuff would be interesting and useful for others. Just as long as we avoid pitfalls like things that would be specific product advertising for companies. How does that sound?

Chris,

Although your request goes somewhat beyond of what I normally share in the public forum, I’ll bite…a little.

I have a graduate degree in EE and undergraduate in Applied Physics. I went to school in Boston in the mid 80’s. I worked for a number of years for the leading microelectronics company in Boston, - did linear circuit design, - DACs, A/D, op-amps, etc. These days I teach electronics and do lots of consulting and indulge in my hobbies. I also briefly worked for Bryston in the mid 90s. Nice company, but it was not for me.

My audio HT set-up is nearly all done by me on a DIY basis. To quote from my profile on htguide, - I have:

Projector:

Marquee 9500 Ultra front CRT projector with DVI input and internal 1080P capable scalar.

Speakers:

DIY 3-way Linkwitz-inspired dipole speaker in the front. Here is the picture of one front channel

http://www.htguide.com/forum/attachment.php4?attachmentid=52

2-way modified Carver Mark IV dipole in the rear. No center channel. DIY sealed sonotube subwoofer with two 15-inch Avalanche drivers, a la Tubezilla (thanks ThomasW). All use heavily modified DCX2496 active digital cross-over in combination with the DEQ2496.

Electronics:

DIY 200 and 400 Watt (4 Ohm) power amps all around. My amps are inspired by Bryston, but they have by far better electronics then even the modern Bryston SST amps. I purchased some older Bryston amps, because I really like the way they look. I gutted them to the core and heavily modified them. I updated output stage, introduced a more sophisticated feedback structure with no electrolytic caps, better transistors everywhere, better input balanced circuit, better stage current balancing and better thermal tracking.

My DVD player is older Sony 975. Meridian 568 controls it all.

My system is fully digital with power amps being the only analog component in the chain. I use balanced signal path.

Currently I am working on a better volume control for my system and still adjusting the subwoofer’s electronics. I am also looking at some superior power amps to introduce a more sophisticated balanced drive for the RD-75 (planer magnetic) sections of my front speakers. The HD-DVD/Blue Ray player is also in the works.

Well, I hope that does it…

Regards,
Victor

[Pez]

Victor - those speakers are impressive. And the fact that you can make your own amps amazes me. I wish had even a fraction of your tech knowledge. I got into this hobby completely blind and after reading posts like yours above makes me realize there is so much that can be to learned. I dont think I would take it to amp building but I would love to try a DIY speaker someday.

[spyboy]

Hi Victor

Your speakers are great looking, and must sound terrific. I like Apogee Acoustics. I thought about buying the Apogee Studio Grand after hearing the Mini Grand. But the $13,000 price tag of the Studio Grand, and the size of them stopped me. A few people have the Apogee Grand.

I would not be surprised if your speakers sound very much like the Apogee Grand.

PS I posted some information in the thread about coaxial digital vs. optical digital interconnects, for your review and comments.

PPS All I need is a spare $85,000 so I can get a pair of Apogee Grands!

[gianni]

Victor,

Glad to see Chris was able to lure you out for a little show and tell.

I've read the majority of your posts here. If I've assembled the bits and pieces correctly, your position is that two properly designed SS amps used within their output capabilities should sound identical, perhaps with the exception if one has had some type of voicing applied. I think you mentioned in one post that Bryston does not voice their amps. Also, you once stated that a Rotel amp versus a Bryston, in the same system will sound identical when used within their limits. Bryston gives you better case work and build but the same sound. Perhaps with the more expensive amps you get better warranty, longevity, channel balance, etc. After some trials of my own, I am really moving towards this end of the camp - well designed SS amps all sound pretty much alike.

My question is: why did you go through the trouble of upgrading your Bryston amps? Because you enjoy it? Just for the satisfaction of knowing the parts are better? Or, is there indeed a significant improvement in sound?

If there is, then that means that Rotel can sound as good as Bryston in a certain sytem but both can be bettered. Therefore, all well designed SS amps do not sound alike. Just when you were convincing me, you throw a wrench into the whole thing.

Thanks,
John

[Victor]

Victor - those speakers are impressive. And the fact that you can make your own amps amazes me. I wish had even a fraction of your tech knowledge. I got into this hobby completely blind and after reading posts like yours above makes me realize there is so much that can be to learned. I dont think I would take it to amp building but I would love to try a DIY speaker someday.

Pez, spyboy

My speakers do sound good. I remember looking at some BW speakers at the hi-end store in Toronto; - they were priced at $30K. I think they were Nautilus 801, but I am not sure.
Anyway subjectively speaking I did like my dipoles better.

I also heard Apogee Studio Grand, and although it is difficult if not impossible to asses the sound quality from memory, my recollection was that there was no day and night difference between the Apogees and what I cooked up. Perhaps the high frequencies were marginally better with the Apogees.

Anyway, - Dipoles have great sound. With my new sub I can get ‘down’ to sub 20 Hz at more then 105 dB of SPL with minimum distortion and that the sounds is great to me.


Making power amps is great fun. However, you need to know what you are doing, just like anywhere else. Having said that, there some very good DIY designs out there that you can try out. No real need for any special knowledge is required up front, just soldering skills. I know people that taught themselves audio electronics by reading articles from Audio Electronics magazines. At this point those guys have some rather impressive engineering skills.

Victor

[Pez]

Victor - have you compared digital amps to ss amps? Based on some of the text in gianni's post if ss amps sound the same does that also apply to digital amps? Just curious and not trying to ruffle any feathers. I joined the digital amp camp and have been very happy, would be interesting to hear any science based info comparing the two.

The longer I work in accounting the more I wish I went into engineering.

[Victor]

Victor,

Glad to see Chris was able to lure you out for a little show and tell.

I've read the majority of your posts here. If I've assembled the bits and pieces correctly, your position is that two properly designed SS amps used within their output capabilities should sound identical, perhaps with the exception if one has had some type of voicing applied. I think you mentioned in one post that Bryston does not voice their amps. Also, you once stated that a Rotel amp versus a Bryston, in the same system will sound identical when used within their limits. Bryston gives you better case work and build but the same sound. Perhaps with the more expensive amps you get better warranty, longevity, channel balance, etc. After some trials of my own, I am really moving towards this end of the camp - well designed SS amps all sound pretty much alike.

My question is: why did you go through the trouble of upgrading your Bryston amps? Because you enjoy it? Just for the satisfaction of knowing the parts are better? Or, is there indeed a significant improvement in sound?

If there is, then that means that Rotel can sound as good as Bryston in a certain sytem but both can be bettered. Therefore, all well designed SS amps do not sound alike. Just when you were convincing me, you throw a wrench into the whole thing.

Thanks,
John

John,

Power amps are linear systems. Our understanding of linear systems goes back to the late 1700s. That is to say we know linear system very well. It is that understanding that tells us that the sound of an amp is a function of its frequency response and distortion. There is nothing else there. Both of those parameters can be easily measured.

We also know what the thresholds of sound audibility in humans are. Again those things are very well known and they have been known for many years, with the first articles appearing in print back in 1930s if I am not mistaken.

Conventional logic would then dictate that as long as the amp does not distort and is kept reasonably linear while exhibiting flat frequency response at audible frequencies no discernable sound will heard that is due to the amp performance.

When one claims to hear what appears to be a discernable sound of an amplifier there is always a logical explanation as to why this happens. This explanation has always to do with measurable deviations from flat frequency response and/or less then acceptable distortion.

The reason I chose Bryston products as a starting point for my amps was two-fold.
I really liked the sheet metal of ST and NRB series amps; - the Bryston box is indeed superb. Bryston’s internal wiring and particularly the circuit board lends itself very nicely to modifications. I also new what needs to be done to make the generic Bryston better.

I want to make sure that it is clear that I am in no way criticizing the engineering choices that Bryston designers made. I simply disagree with a lot of them. I have my reasons and I can defend them. Furthermore I was not trying to produce an amp by the hundreds, so my views are geared to the one-off amp. Clearly the manufacturing reality dictates the choices that can often be seen as cutting corners. Engineering is all about compromises.

So, - I upgraded Bryston amp in order to get a better engineered product. I made sure that circuit topology reflects modern circuit design ideas, while preserving what I thought was actually quite good, - Bryston’s output stage. However I did change the transistors. Interestingly enough the current SST series also uses much better output transistors.

I improved the power supply that I considered one of the Bryston’s weak points. I changed the feedback network and got rid of offending electrolytic capacitor. I re-biased the voltage gain stages and made them more stable. I change the temperature tracking circuit so that the bias current no longer wonders. I introduced active load and active bias current control. Finally I changed the balanced input circuit which is another weak point in my opinion.

The end result is by far more stable amplifier with distortion specs marginally better then the current stock unit. It makes me feel better to know that I have a better engineered product. As far as its sound quality is concerned, it made no difference that I can tell in my opinion.

Regards,
Victor

[Alaric]

Victor , that is one stunningly beautiful speaker system. I have no doubts as to the sound quality of the build , but you should certainly be complimented on the obvious craftsmanship , as well. :T
And , yes , I have tried the coat hanger/speaker wire thing a few times now. Damned if it doesn't work like a charm.

[Victor]

Victor - have you compared digital amps to ss amps? Based on some of the text in gianni's post if ss amps sound the same does that also apply to digital amps? Just curious and not trying to ruffle any feathers. I joined the digital amp camp and have been very happy, would be interesting to hear any science based info comparing the two.

The longer I work in accounting the more I wish I went into engineering.

Pez,

To date my experience with digital amps had been less then satisfactory. However, the only amps I looked at were the pro-types and they have rather high distortion.

The appearance of UcD modules from Hypex changed all that. UcD design is different from all other designs I have seen. UcD’s feedback loop includes the output filter. This alone is responsible for the more then adequate THD numbers. Add to this equation a small size, high efficiency and absents of heat and you got a winner.

I think the future belongs to Hypex. I would not hesitate to outfit my HT with UcD-based power amps. It is on my list of things to do for this summer to actually acquire an UcD400 unit and look at.

As for the sound, well, the same logic applies here. UcD amp is clean enough to be indistinguishable in a blind test. I have not done this, but this would be my call.

regards,
Victior

[Victor]

Victor , that is one stunningly beautiful speaker system. I have no doubts as to the sound quality of the build , but you should certainly be complimented on the obvious craftsmanship , as well. :T
And , yes , I have tried the coat hanger/speaker wire thing a few times now. Damned if it doesn't work like a charm.

Alaric,

Thank you for your kind words. I must confess that I only participated as a helper in my speaker contraction. I have a friend who is a master cabinet maker, he led the charge. I did design the entire thing though with some help from this forum members.

Certainly the active digital cross-over implementation is also my doing. Right now I use a modified off the shelf unit, but I am looking at a circuit board from UK with better digital filters and great software to boot. I may change the cross-overs this summer.

regards,
Victor

[Pez]

Victor - Thanks! Interesting stuff indeed. When I bought one I asked the salesman his opinion on the amp and his answer was a bit odd and basically trashing them.

[cobbpa]

Hey Victor, just saying thanks for posting your experiences & sharing some knowledge..I realize it takes some time and really appreciate it, as I sure many members here do. Totally over my head, but interesting to read regardless!

[Chris D]

Wow, this already is over my head. Victor, nice speakers, and yes, I'm in awe that you have "DIY amps".

What's this coat hanger thing? What did I miss about it?

[Victor]

Wow, this already is over my head. Victor, nice speakers, and yes, I'm in awe that you have "DIY amps".

What's this coat hanger thing? What did I miss about it?

Great many people have DIY electronics with power amps perhaps being the most popular DIY items. If you visit diyaudio website you’d be surprised to discover the magnitude of the ‘addiction’.

In my posts I guess I tend to get overly technical, perhaps I should not, but I do not know how else I could describe the modifications. I will try to change this.

The coat hanger thing was me shooting from the hip in anger, - something I posted a while ago to illustrate the effect of speaker cables on power amp-speaker interface.

As I recall this was a mighty battle of megabuck Kimber super-wire verses four coat hangers from my closet. I chose a particularly old and rusty ones. Using a pair of bookshelf Tannoys (Eaton model with nice coax drivers) and a pair of Bryston monoblocks, I think they were, I demonstrated that no statistical difference could be heard between the Kimber wire and two opened hangers with twisted and filed ends.

I used pliers to twist the ends of two hangers together and some electric tape to achieve the length comparable to the runs of Kimber. I made`two runs of hanger wire, - one for the signal and one for the ground. I filed the other ends and plugged them into the speaker receptacles and the amplifier output connectors.

The Tannoys are surprising clean and accurate monitors and the power amps were reasonably good too. Well, - out of two dozen or so people who took part in the test nobody could consistently identify one wire or the other. Naturally I do not advocate the use of hanger wire, but the experiment does speak for itself


regards,

Victor

[Alaric]

What's this coat hanger thing? What did I miss about it?

Oh , boy. Chris , get a few uncoated clotheshangers , move your main speakers really close to your amp . Now use the straightened out hangers for speaker wire . I'm not giving up on CAT Cables , but you gotta try it to believe it.
Personally , I dig the quality , look , and performance of really high quality cables. CATs are tops in my book. I'm slowly (really slowly) gathering my cables from Doug , but the wire hanger thing (Joan Crawford forgive me) is a real eye-opener. As my speakers weigh 70 lbs. each , a repeat of this experiment indicates I found something worth noting. :E

[Alaric]

The coat hanger thing was me shooting from the hip in anger, - something I posted a while ago to illustrate the effect of speaker cables on power amp-speaker interface.

Yeah? It got my attention. It also shut my "know it all" trap right the heck up. The thread rightly proved that if I "knew" everything I thought I knew , I still didn't know enough to question Victor's conclusions. If I doubt something Victor claims , I sure as heck won't do it publicly! On the plus side , I realize I don't know enough to doubt him at all . (Still love CAT Cables . Even if I can't prove they're better-I like them-love the sound , build quality , and the customer service.) If I'm starting to sound like a commercial , well , ok.
Geez. Build your own amps? I finally nailed correct wire soldering and thought I accomplished something! That's what I get for thinking....

[bigburner]

Thank you for the background information Victor. I always enjoy your posts. They really add value to this forum.

Regards,
Nigel.

[Brandon B]

Crap, so I pretty much wasted my money on getting nice new clean coat hangers from the dry cleaners?

Seriously, I have had a 4 channel UcD amp from Exodus running in my main system for most of a year, as I moved my older Odyssey Stratos up into my 2 channel music system. I have to say I really, really like the UcD for all the reasons Victor points out. Small, runs cool, sounds really good, absolutely nothing to not like about it. I had bought it as a 4ch 180 watt, but it runs my maggie 1.6's pretty well. I am going to add a 2 ch UcD400 for those, and use the 180 for the surrounds as I originally intended at some point. Can't decide if I would add a channel into the 180 for an eventual maggie CC, or if that would warrant a 3 ch 400W.

I also have to admit, when I first got it and listened to it, it seemed I heard some improvement over the Odyssey. I believe Victor commented at the time that if I did some careful testing he would be surprised if I really heard a difference, and over the months I have had both, I'd have to agree with that assessment.

BB

[Victor]

I am in no way trying to advocate the use of hanger wire. The experiment was a joke really. But it did show that the wire does not need to be exotic in order to function well.

I know we all have our little compulsions when it comes to wire and it is a painful topic for many people. I say, - use whatever turns you on! In the end it will not make as much of a difference as you think.

I use plain vanilla 12-guage jacketed Belden 8477 speaker cable. It comes in 500 feet roll. Since my front speakers are active 3-way, and the rears are active 2-way, plus I have an active sub, - it adds up to 11 channels, - I need quite a bit of wire.


Victor

[Race Car Driver]

Interesting read

And as with everyone else, Nice DIY on those speakers!!! Those modded Brystons would be cool too Now I know where all your Bryston knowledge comes from.

Chris

[Victor]

Now I know where all your Bryston knowledge comes from.
Chris

Chris,

There is no such thing as “Bryston knowledge”. Bryston’s technology is an open book, as it is open to anybody and accessible by all. Bryston’s website lists the schematics and complete descriptions of successive variants of all Bryston gear.

Once you have a Bryston power amp, you can download the schematic file and you can be off to the races to whatever modifications you may have in mind. I like this particular aspect of Bryston company philosophy, - they hide nothing.

Victor

[kingpin]

Hi guys.

I post mostly on the Missions Accomplished Section but have lurked through here just as much.

Victor, was just curious price wise, what the cost of the amps you built are.
You can pm me if you like or post it here.

BTW. Your speakers are simply beautiful. I hope when I get a chance to put a finish on mine they look half as good as your.

Mike

[Victor]

Mike,

Are those dipoles in the picture next to your name? They look like the Bethhoven’s on steroids. My amps are DIY boxes and as such they have no price. There is a cost to modifications that I did, but it is not all that high, it is mostly the time it took to fix them up.

Regards,

Victor

[kingpin]

Mike,

Are those dipoles in the picture next to your name? They look like the Bethhoven’s on steroids. My amps are DIY boxes and as such they have no price. There is a cost to modifications that I did, but it is not all that high, it is mostly the time it took to fix them up.

Regards,

Victor

Ha Ha. :B :B
No they are not Beethoven's on steroids. They are cjd's(forum member) design, turned upside down with the addition of 2 12" subs on the bottom.
I have since turned them upside down again so the subs are on top as they sound much better this way. All sealed in one tower. They took me 6-7 months to build and they still have no type of finish(veneer) on them.


They don't have a name yet but they will soon enough. I am trying to find a name that suits a 500lb(just shy) speaker.
Maybe I will call them the "Herniators". :B

I can't even solder, although I will learn when I build my center speaker, so gentleman like yourself who can build an amp and have fun with electronics make me extremely jealous. Not something I have the knowledge to be able to do. Trying to understand crossovers has been a failed challenge.

Appreciate your time Victor.
Mike

[bigburner]

I think the future belongs to Hypex. I would not hesitate to outfit my HT with UcD-based power amps. It is on my list of things to do for this summer to actually acquire an UcD400 unit and look at.

Please keep us posted on this project Victor. The brief research that I have done on Hypex has made me contemplate becoming a DIYer. A 2-channel amp based on the UcD400 unit looks very appealing.

Just out of interest, do you know if there are any manufacturers selling 2-channel amps based on the UcD400 unit?

Nigel.

[Victor]

I can't even solder, although I will learn when I build my center speaker, so gentleman like yourself who can build an amp and have fun with electronics make me extremely jealous. Not something I have the knowledge to be able to do. Trying to understand crossovers has been a failed challenge.
Mike

Mike,

You speakers look good and I am sure the sound lives up to the look just as well. It is truly amazing what you can do on the DIY basis. Once you started on this path, it is next to impossible to ever consider a commercial product.

As for crossovers, I suggest that you invest in a DCX2496-DEQ2496 combination and a M8000 microphone. It will enable you to configure things at will without worrying too much. You can change things just as easily. Many pro-shops in Toronto carry those boxes.

Going with active crossovers will require an addition of a separate power amp per driver. As I mentioned the UcD modules represent a significant challenge to all power amp manufacturers. The UcD module is powerful, clean, cool and inexpensive. You can easily put 3 or more in a single box and not worry about heat management or anything else for that matter.

This would make a great DIY project. You can get a kit with all the parts included and put it together yourself. As an added bonus your speakers will sound a lot better because the passive crossovers are gone and with them the energy storing elements such as large caps and inductors are gone also.

The driver cone control is now in the ‘hands’ of the power amp and its output resistance. This would literary mean that when the amp ‘says’ ‘stop’ the cone stops and when the amp ‘says’ ‘go’ the cones goes. No inertia issues and no hesitation and consequently and most importantly by far less distortion.

Regards,

Victor

[Victor]

Just out of interest, do you know if there are any manufacturers selling 2-channel amps based on the UcD400 unit?

Nigel.

Nigel,

Yes, there are several out there.

For instance, Diycable.com sells pre-made units as well as the kits based on various UcD modules. Look here

http://www.diycable.com/main/default.php?cPath=140&Cid=3ff851eb92b4028729c46fc3072657f1

2-channel 180 watt unit will cost under $900 with some worth whole options. The 400 watt unit might cost another $200-300. Alternatively you can simply buy the modules directly from Hypex for about $100-150 each and put it all together yourself. It is not difficult from what I can see.

Regards,

Victor

[Brandon B]

Kevin at the link you posted will also sell you parts, he is a hypex distributor. I bought my 4 ch 180 from him assembled as I was shorter on time than cash at that point. He also has a lot of good accessories to go wih the modules like toroidal transformers with the wiring output for the soft start and other features the hypex units have.

BB

edit: tordoidal is not a word

[bigburner]

Thank you Victor. The Exodus UCD400-2 MCH Amplifier kit looks very interesting. It looks so simple that even I could build it, bearing in mind that my last DIY electronics project was building a crystal set at age 9...

What are the advantages of buying the modules directly from Hypex and putting it all together yourself? Is it the fun of doing it yourself, or a better price, or do you purchase superior components and therefore get a better amp? For example, are there any changes that you would make to the Exodus kit?

This thread has got me reading the Mission Possible DIY section and I'm intrigued. I see that the UcD400 unit has already been used in a few projects.

Nigel.

[Victor]

What are the advantages of buying the modules directly from Hypex and putting it all together yourself? Is it the fun of doing it yourself, or a better price, or do you purchase superior components and therefore get a better amp? For example, are there any changes that you would make to the Exodus kit?

Nigel.

Nigel,

I found that the hardest part of making the DIY amp is the metal work. The electronics is normally the easiest; because it has already been worked out by somebody else unless you are doing the design from get go.

If you are in fact the original designer of the amp project then it may be quite difficult to get thing right. I try to avoid doing original designs because it takes a fair amount of time to do it and in the end you end up duplicating to some degree the well known circuits anyway and I like to get things working as fast as I can so that I can enjoy the end product, - music or movies.

If you do not buy a kit, then you need to think through the metal box configuration, the wiring, the power supply, the protection circuitry etc. This will take time! Can you make the UcD modules better? I am sure you can, but do not expect the day and night difference because the modules are quite good to begin with, - it is a more an icing on the cake here. Look here

http://www.diyaudio.com/forums/showthread.php?s=&threadid=91567

and here

http://www.diyaudio.com/forums/showthread.php?s=&threadid=38199&highlight=

and particularly here

http://www.diyaudio.com/forums/showthread.php?s=&threadid=58873&highlight=

So, - in the end you will save money by purchasing the modules only, but I am not sure if the uncertainty of the end result is worth the savings. You must know how to interface the power supply to the amp modules and do the proper wiring with safety in mind. My suggestion, - get a 2-channel kit first, learn what it takes to get things right, and afterwards perhaps do a multi-channel amp all by yourself.

Regards,
Victor

[bigburner]

Good advice and interesting threads thank you Victor. No shortage of conflict in that first thread!

Nigel.

[Martyn]

As for crossovers, I suggest that you invest in a DCX2496-DEQ2496 combination and a M8000 microphone. It will enable you to configure things at will without worrying too much. You can change things just as easily. Many pro-shops in Toronto carry those boxes.

It's hard to find Behringer gear discounted in Canada like it is in the US - on the west coast, anyway. The best I've found so far is studica.com (especially if you can qualify for educational pricing).

BTW Victor, I enjoy your posts too so keep 'em coming.

[Kobus]

BTW Victor, I enjoy your posts too so keep 'em coming.

Agreed 100%,
not with the content always, but with the discussions in general.

Kobus