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All the info you are looking for is located @ DIY Audio.Link: http://www.diyaudio.com/forums/forumdisplay.php?forumid=49There are several long threads but all the info is there.
The so called modifications are really very minimal. A couple parts substitutions and bypassing the DC blocking caps. Just understand if your source has any DC transient it will be amplified and possibly damage your speakers. It's a risk you take when removing DC blocking.
Quote from: Kevin HaskinsThe so called modifications are really very minimal. A couple parts substitutions and bypassing the DC blocking caps. Just understand if your source has any DC transient it will be amplified and possibly damage your speakers. It's a risk you take when removing DC blocking.I can't actually think of any good reasons for removing coupling caps, nor for a "DC" amp or preamp.
Dear Sir,I have experience that a low quality cap in series with the signal influences the sound not for the better.And good ones are usually very expensive and quite big (PP et similia).It is a very important component indeed.Of course removing it can cause some problem.Kind regards,beppe61
Dear Mr. Haskins,please excuse me but only now I understand your are the owner of DIYCABLE company.First of all my most sincere congratulations for your great creations !Then thank you so much for spending your time giving such valuable advice to me.It is very kind of you.
Hi Beppe61, Well, from what I read on the DIY forums, get the one with the AD8620. Now if you are aware of what is up the electronics chain, you can try shorting out the input caps. The "offset" voltage appearing at the output is very low. Shorting the imput caps, would give you the knowledge of whether keeping them or removing them would be worth the time. Unless, you go the Channel Islands route, or get the Stan Warren UCD amp, don't think you will go to much wrong here. Just some simple ideas to try.Ray
Dear Mr. Bronk,thank you so much for your very kind and valuable advice.Now I have another problem: will the UcD 180 power module be powerful enough to drive adequately my "hungry" Dynaudios?From the data sheet I understand they are current limited at 10A max.Then only time I heard my Dynaudios sounding nice was with two little monos able to deliver 22A of peak current each !They are very demanding speakers in term of current.Bedises the UcD 400, limited at about 20A, could be a wiser choice.
Hi Again, Well, Kevin could give you a little more info on this. Never played with either the Modules or the Dynaudio speakers. By now I have tested a lot of amp with these speakers and most of them have failed to drive adequately.The bass is slow and soft.If you have ever listened to the bass from a JBL speaker, it is exactly the opposite.The woofer in the JBL seems made out of wood, in the Dynaudio out of rubber !To make a Dynaudio woofer sound like a JBL one I think something like a Krell is needed (high current delivery).I heard the Dynaudios sound fine with two old (1990) UK monos 45W/8 ohm each but with a peak current of 22 Ampere.> Probably the UCD400 would be the wiser choice.I start to think the same. Max peak current in the order of 20 A.I understand that the UcD400 is also used in a pro amp for bass players (high current demand). So it should be just fine.> The definite key is a good stout power supply. That is what I thought. But now I understand that most of commercial amps use some kind of current limiting circuits in order to safeguard the ouput devices from breaking-down for stress.In my case this has very bad consequences in term of sound.Maybe a wiser choice would be to abandon these hungry speakers.> That's all I can tell you for now. Ray
Dear Mr. Bronk,thank you very much for your kind reply.Let me please be more precise between the lines.> Dear Mr. Bronk,thank you so much again.If you are aware of high current amp kits please tell me.Kind regards,beppe61
Well, since you likve in Italy, you might do well to get all of the stuff through Bruno who makes the Hypex kits. If memory serves me right, he lives in Belgium. You want at least a 500 or 600VA transformer for the UCD400's. Dear Mr. Bronk,I have to say that Ucd 400 power modules are very high in my most wanted list.The 20 A max peak current should be just fine for me.I am just waiting for the presentation and feedback from the next January CES where there will be a lot of products based on these modules.> I don't know what the limiting factor would be, but a to big transformer, and it will slow down the amp. For me a slow amp is an amp with low damping factor and current delivery.We perceived the slow movement of woofers out of control.> Go up to the DIY audio forum and read all the comments on the power supplies for the UCD stuff. I read about different choices between toroidal and EI transformer.But I understand that a nice powerful toroidal should be just fine.> Stan Warren is using a 600 VA transformer in his application of the hypex stuff. Those ...
