UCD180 questions

Jump to Latest
#1,684
Ok I won't be finding that one again this year.

I gave you his logic on it anyway, maybe someone else has seen the same site and can post it.

You could possibly use a voltage doubler of some sort just to give it an initial slam too, or one of those "relay power savers".. which seems to do the same.

Good luck I quit.

zzzzzz
 
#1,685
classd4sure said:
http://www.astro.uu.se/~marcus/private/dcprot.jpg

No that's not the link but .... what the hell.

Good luck I quit.
Click to expand...

classd4sure, thank you anyway.

See this link:

http://sound.westhost.com/project33.htm

Here I can see the two relays RL1 and RL2 in series (actually I took the PNP driver section here). The dc level "comparator" circuit is also same than on above link but it was used on some other circuit too (which was much more complicated).
Anyway, Rod says taht ".. this circuit cannot be used as shown with the 12V relays in series if the supply voltage is less than +/-24V ". So that makes me a little bit suspicious. If you could run the circuit from the UcD supply directly you could save some components (regulator / zener etc., there is no 12V supply, it must be done separately).

Two 24V relays in series might work, or two 12V in series and a resitor in series with them (like in ESP project #33).
 
#1,686
Re: re cheap soft-sart.

I apologize for a very "delayed" thank-you to ClassD4sure and Bob Lewis. I had connection troubles :angel:

I realized that I do need a small TX to power a speaker output DC detector anyway so I'll stick to my first aproach: sofstar + DC detector from Ampslab.com for my UCD400 and leave my "cheap softstart" for my UCD180 "secondary" system.

Thanx again.
Mauricio
 
#1,687
mhelin said:


classd4sure, thank you anyway.

See this link:

http://sound.westhost.com/project33.htm

Here I can see the two relays RL1 and RL2 in series (actually I took the PNP driver section here). The dc level "comparator" circuit is also same than on above link but it was used on some other circuit too (which was much more complicated).
Anyway, Rod says taht ".. this circuit cannot be used as shown with the 12V relays in series if the supply voltage is less than +/-24V ". So that makes me a little bit suspicious. If you could run the circuit from the UcD supply directly you could save some components (regulator / zener etc., there is no 12V supply, it must be done separately).

Two 24V relays in series might work, or two 12V in series and a resitor in series with them (like in ESP project #33).
Click to expand...

That's the circuit I was looking for last night! You had it alllllllll along hahah.....

I think I was thrown with who's site it was on because it's Rod Elliot's but he references Doug Self at the bottom.

Well you have some options anyway, personally I see no reason why you couldn't power it from the amp's supply.

One down side I see to it that I'd like to point out to you, should later on decide you'd like your protection circuitry to shut the supply down based on whatever condition you like.... you'd then want a reliable (very simple) auxiliary supply to power all protection circuitry. It's a little more well rounded I guess.

Mauricio, thank you 🙂

Salut,
Chris
 
#1,688
mhelin said:
Thanks Steven and Roger!

The Krell circuit looks good, nice idea to use the emitter to bias the Q201 on negative voltages. However, the circuit works opposite way to the previous one, it pulls the relays after the startup timer (R203, C204), and in presence of DC it disconnect the speakers. Four parallel switches is nice (for speakers).

So about the time constants, C202 & C203 can propably be replaced with a non-polar 22uF + the TVS.
From Q201 and Q202 collectors to the relay driver PNP (from the previous circuit) is the 22k resistor OK, or should it be much smaller to give more base current and because of the reduced beta at low Vce (though it's 400 for the pnp driver at this current)? The Ib with 22k is just 0.5 mA and with beta of 400 the Ic would be about 200 mA (it still enough to pull the relay though). I would like to use 10k there, is it ok? Also the 2k resistor sinks some of this current (0.6V / 2k = 0.3 mA). How about connecting a 0.1 uF speedup cap across this resistor (22k or 10k or whatever you use)?
Also I can't find the ZTX692B (70V, 1A) from Farnell (Finland), closest are ZTX690B (45V, 2A Ic) and ZTX694B (120V, 0.5A Ic). The latter should be ok?
~Mikko
Click to expand...

Mikko,
Yes, C202 and 203 become one 22uf nonpolar cap. C204 not used, it was a turn on delay but also drastically slows turnoff with a neg voltage fault. D201 out, as it has no function. D202 can be a 1N4004. R205 S/B a 2k to insure turn on. All transistors can be the ZTX690B.
I guess you are going to use this as a speaker disconnect in series with the output? You only need one relay and one of this circuit for each channel. The relay can be one of the sensitive 30 amp automotive types. Using a 4 pole relay with all contacts paralleled still leaves you with one closing first and one opening first so circuit interruption is only as good as any one set of contacts. Also there is the multiple signal path thing to be considered. Use a separate small transformer to power both boards. This transformer should have 2 equal 12VAC secondarys so you can build 2 separate power supplies, one on each board. (Bridge rectifier, cap and 7812 reg.) This allows you to keep the ground connection for the input signal reference only and not form a ground loop between the channels through this power supply ground connection.
This leaves the soft start as a seperate thing. Wouldnt want full line voltage on the same board/relay anyway.
Roger
 
#1,689
DC Protection

Thanks to everyone,

This discussion is starting to be a little bit off-topic, and because there are now enough options for building the DC protection circuit (Roger, it will be for the PSU disconnect, not for the speakers, also like Chris suggested an aux supply does indeed seem a better solution for powering the circuit) it would be good to close this subject here and continue on basic UcD questions.
Anyway, if there's still interest on this subject then please start a new thread (refer to this thread). This is a too long thread already.
~Mikko
 
#1,690
Since I am too lazy to look for the answer on the 165 pages of posts on this thread, I'll just ask again...

There is any functional difference between the ucd180st and the ucd180ad modules, like different gain, dc decoupling method, or input impedance? I am going to buid a 4 channel amplifier for linkwitz's orions, like Pasi did, but I am trying to reduce costs by using the st modules for the woofers, and the ad modules for the tweeter/mid, but I must be sure the basic behaviour of both versions is similar enough...

Thanks,
Allan

ps. If weren't for the local taxes, i would go ucd180ad all the way...
 
#1,691
ninjanki said:
Since I am too lazy to look for the answer on the 165 pages of posts on this thread, I'll just ask again...

There is any functional difference between the ucd180st and the ucd180ad modules, like different gain, dc decoupling method, or input impedance? I am going to buid a 4 channel amplifier for linkwitz's orions, like Pasi did, but I am trying to reduce costs by using the st modules for the woofers, and the ad modules for the tweeter/mid, but I must be sure the basic behaviour of both versions is similar enough...

Thanks,
Allan

ps. If weren't for the local taxes, i would go ucd180ad all the way...
Click to expand...

Only difference is the input opamp. For the rest its the same.
You can use it the way you want to use it.
 
#1,696
Hi,

Absolutely there is! Make no mistake there.

See it's just like Roger was saying the other day, we can't write novels in response to a general question and look at the size of this thread already.

I just answered it in the context of his post, assuming he's willing to live with the sound quality of the ST module's op amp.

Actually I'd also like to point out that he could replace the 5532 op amp with a very affordable opa2134 (2 or three bucks each?) and that would indeed allow him to DC couple should he so desire, and likely sound better, at a much reduced price than to go buy the AD op amp.

🙂
 
#1,698
Hi

What's that got to do with the context of the question, which went something like:

"There is any functional difference between the ucd180st and the ucd180ad modules, like different gain, dc decoupling method, or input impedance?"

If he wants to DC couple his amps, then there is a functional difference, since the op amps then must be upgraded, and you can't just do as you say, "anything you want with them".

By the way, if you'd like to post the extensive measurements you've done I'm sure we're interested in seeing them.

Also, when referring to such measurements, it would be most useful if you used the standard naming conventions so that we may all understand, after all, that's what they're for, right? I've been wondering for weeks where you came up with "kc".

Regards,
Chris
 
#1,699
Kc? KHz?

classd4sure said:
Hi

What's that got to do with the context of the question, which went something like:

"There is any functional difference between the ucd180st and the ucd180ad modules, like different gain, dc decoupling method, or input impedance?"

If he wants to DC couple his amps, then there is a functional difference, since the op amps then must be upgraded, and you can't just do as you say, "anything you want with them".

By the way, if you'd like to post the extensive measurements you've done I'm sure we're interested in seeing them.

Also, when referring to such measurements, it would be most useful if you used the standard naming conventions so that we may all understand, after all, that's what they're for, right? I've been wondering for weeks where you came up with "kc".

Regards,
Chris
Click to expand...

Chris
You are betraying your age. Kilocycles (KC) and megacycles (MC) used to be the standard way of naming freq. I think it was the late 60's it was changed, just looked it up and the amateur radio log stated it was 1970 that it was officially changed.
Roger
 
#1,700
Thanks to Hypex

I want to thank warmly Jan Peter and Bruno for a wonderful birthday party 😀

One day before my projected party arrived the Epcos Sikorel caps pair (10000 uF/63V) to split my 4 channel UCD180ST amp in two stereo amps. I wired everything in less than 24 hrs 😎 into my DIY box.
Guess what, I forgot to twist the PS cables 😱 and we were talking about that these days!

Do you have noticed that UCD's aren't aggresive sounding even at party volume level? It is more than lack of clipping I guess. One can dance next to speakers without ear fatigue. Bass is extended but not oppresive, wich some may miss.

When all is broken-in I will compare the sikorel's to BHC ALS40.
My first impression is that they sound more clear and detailed but this could be the effect of spliting the 4ch amp: sikorel based amp to the midrange-tweeter and BHC based amp to the bass speakers.

Regards
Mauricio
 
You must log in or register to reply here.
Top Bottom