Those are in wall mounted, infinite baffle design. It's Raven 2 on top, crossed at 12k with a single Siemens MKV cap. There are two mid woofers in MTM config. Triangle runs full range and PHL crossed from top, provides mostly the bottom end fill up. Each woofer has 12 ohm nominal impeadance.
matjans said:
Matjans,
http://www.conrad.nl sells these (look for lt-1083) for the price of €17.46 and you need two.
I like the LM338 much better for gainclones powersupply. It's available from "display" distributors (see http://www.dos.nl for shops)
Maarten
peter - to me it sounds like you are describing something sub optimal....there is a limiting factor somewhere.
if it were me i would use the lt1083 - and only for the power chips, and your tvc direct in the non inverting gc.
btw read the data sheet for the lt1083- it's not the same as the lm338.
10000uF/63V cerafine before the regs - 0,1uF "superfilm" right on the input pin on the reg - 100uF bypass the adj pin - regs close to the load and a 470uF (silmic) on the output pin.........rock'n roll....😉
if you choose to "double regulate" (c) tbla2004......you have my permission.......😀
if it were me i would use the lt1083 - and only for the power chips, and your tvc direct in the non inverting gc.
btw read the data sheet for the lt1083- it's not the same as the lm338.
10000uF/63V cerafine before the regs - 0,1uF "superfilm" right on the input pin on the reg - 100uF bypass the adj pin - regs close to the load and a 470uF (silmic) on the output pin.........rock'n roll....😉
if you choose to "double regulate" (c) tbla2004......you have my permission.......😀
Of course, an important point. While I'm sure Peter enjoys being an "authority", I'm sure he also doesn't enjoy the problems associated with it 😉
Well, as I am sure he would agree, Peter is one only one data point, as I'm sure Carlos would agree. I hope others will make the amp and give us their impressions also. There is no doubt that on another system it might sound quite different.
That's one reason I'm taking the amp to my listening buddies tomorrow, to see what they think about it. My opinion counts only for me, and others might have a different POV.😉
Re: Re: "Inner Voices"
I disagree 2x.
You did not understand the meaning of the term "inner voices".
You did not pay attention. I did post a complete low noise regulator but no-one noticed it or did comment. Not even one "collecting facts"......
http://www.diyaudio.com/forums/showthread.php?postid=422675#post422675 and below.
Pearls for the swines...
🙄 
Peter Daniel said:
I disagree 2x.
You did not understand the meaning of the term "inner voices".
You did not pay attention. I did post a complete low noise regulator but no-one noticed it or did comment. Not even one "collecting facts"......
http://www.diyaudio.com/forums/showthread.php?postid=422675#post422675 and below.
Pearls for the swines...
🙄
If I may provide some constructive input regarding input buffer, I would suggest that more care should be taken with PS on that thing. I did some tweaking with my ML preamp and I sort of have idea what works well. The biggest gains were obtained by changing PS components. I also don't believe in double regulation, each time regulator is added, the dynamics are diminishing.
I'm using MUR860, followed by BG caps. The caps before regulators are as important as the ones after regulators. I'm using 1000 STD BG at the rectifiers and then additional 1000/50 N type right before regulators. I changed generic 78/79 regulators to LM2990 and LM2937 and the difference was quite big. Those are low drop regulators, so I'm not sure with how high input voltages they accept. At the moment I'm only using 4.7 BG N after regulators, but plan to put 10u there. Again, this cap makes quite a difference.
In ML preamp, the gain stage is made out of LT1217 and is followed by OPA2604. I don't think I would like to change anything here, as it sounds fine to me. The bypass on those chips consisits of those blue Vishay caps, 0.01u value (this in addition to 330u somwhere on the board). They were the best from what I tried, better than green Wimas and better than the best grade panasonics from DK.
I'm using MUR860, followed by BG caps. The caps before regulators are as important as the ones after regulators. I'm using 1000 STD BG at the rectifiers and then additional 1000/50 N type right before regulators. I changed generic 78/79 regulators to LM2990 and LM2937 and the difference was quite big. Those are low drop regulators, so I'm not sure with how high input voltages they accept. At the moment I'm only using 4.7 BG N after regulators, but plan to put 10u there. Again, this cap makes quite a difference.
In ML preamp, the gain stage is made out of LT1217 and is followed by OPA2604. I don't think I would like to change anything here, as it sounds fine to me. The bypass on those chips consisits of those blue Vishay caps, 0.01u value (this in addition to 330u somwhere on the board). They were the best from what I tried, better than green Wimas and better than the best grade panasonics from DK.
Peter Daniel said:
Do you consider that a good pre? Gotta run!
Definitely, there's some problem with your tests, your amp, your pre, your PSU, whatever.
🙄
I don't think it's that much the matter of parts (or chips) but rather the implementation. I have plans to try other IC's in this place, but I don't think I will get much of an improvement.carlosfm said:
Gotta run!
Definitely, there's some problem with your tests, your amp, your pre, your PSU, whatever.
🙄
As I mentioned already, PS is the area to look into, and yours is not optimal. It's as simple as that.
I don't know what one should consider a good preamp, I only know when it sounds good.
tbla said:
Forget it, tbla...
It could get even worse.
The LM338 sounds very good to everyone, except Peter.
But as I don't trust his layout (sorry), with little boards all over the place, a mix of PCB with veroboard, with P2P, i don't take this too serious.
Peter, your oppinion is not important to me, I know what's best for me and curiously other people have tried and love it.
I was expecting an oppinion like this, and I was expecting that you compared this with batteries instead of the unregulated PSU.
Well, life goes on.
Let's see what your partners say, if that matters.
At least leave the amp
in' in.Peter Daniel said:
I was talking both.🙄
From your discription, that bypassing is miserable.
And THIS is much more important than regulator types, fancy caps, etc.
And those chips are nothing special...
carlosfm said:
I was talking both.🙄
From your discription, that bypassing is miserable.
And THIS is much more important than regulator types, fancy caps, etc.
And those chips are nothing special...
Look, I even placed sockets to be able to try all different types of caps. Those work really well. What I also do is checking ea. cap for outer foil and place it in a circuit accordigly. Maybe that's the secret.😉
I didn't even use the fancy caps yet. The electrolytics are still the stock ones and I'm waiting for my BG order to arrive.
And BTW, everything matters.
Attachments
carlosfm said:
Letting it pass that you use the words "everyone, except Peter" when you must mean "several people, but not Peter", doesn't this just confirm what everyone already knew?
People have differing opinions (you might even use the word "priorities" here) as to what is good. If this were not true, everyone in the world would be using the same gear.
The only way to know what something sounds like is to listen. At least you guys are trying. For that, I salute you. Some misguided people think they'll get "the best" by *reading* DIYAudio.com.
My point is this: you have a far better chance of getting sound you like by spending your budget and time building two different amps than you do by spending all of your budget and time on one amp.
Here's a board design for the regulator.
What does everyone think? I have removed the ground traces, and substituted star grounds as it eliminates the problems with the ground having to snake all over the board requiring a double-side PCB. I vertically stacked the resistors as it make the board much smaller.
The previous board didn't have an output yet because it was 2:00 am and I wanted to show what I had done so I could get some input on it in the morning. Like I said, it was partial.
I don't know if I will use this arrangement at all, but I wanted to see what I could do, and it would at least get me working on the project while I have some time but not enough money to proceed.
I also think it will sort out any issues I have about understanding the design.
An externally hosted image should be here but it was not working when we last tested it.
What does everyone think? I have removed the ground traces, and substituted star grounds as it eliminates the problems with the ground having to snake all over the board requiring a double-side PCB. I vertically stacked the resistors as it make the board much smaller.
The previous board didn't have an output yet because it was 2:00 am and I wanted to show what I had done so I could get some input on it in the morning. Like I said, it was partial.
I don't know if I will use this arrangement at all, but I wanted to see what I could do, and it would at least get me working on the project while I have some time but not enough money to proceed.
I also think it will sort out any issues I have about understanding the design.
Peter Daniel said:
😱
U-n-b-e-l-i-e-v-a-b-l-e.
Peter Daniel said:
😱
Incredible.
What do you know of my PSU?
You only saw my schematic.
And you did a bad job out of it.
You can put your better regs and fancy caps and you may get improvements, but you can make a good layout and you may not need those regs or fancy caps.
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