| e.lectronick |
Okay, I just looked at the PDF form on the changes to the rev 3 boards again, and I think I get it, now.
The rectifier boards and the Snubber PS boards both allow for the Snubber PS to be implemented, right? The 10000UF caps are placed (optionally) underneath the board which is raised using standoffs to accomodate them.
So, If I just purchase a set of the Rev 3 boards with their accompanying rectifier boards, I don't need to purchase a Snubber PS kit too, right? Assuming I get my own parts, the included rectifier boards will allow implementation of the Snubber PS?
-Erik |
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| BrianGT |
| quote: | Originally posted by e.lectronick
Okay, I just looked at the PDF form on the changes to the rev 3 boards again, and I think I get it, now.
The rectifier boards and the Snubber PS boards both allow for the Snubber PS to be implemented, right? The 10000UF caps are placed (optionally) underneath the board which is raised using standoffs to accomodate them.
So, If I just purchase a set of the Rev 3 boards with their accompanying rectifier boards, I don't need to purchase a Snubber PS kit too, right? Assuming I get my own parts, the included rectifier boards will allow implementation of the Snubber PS?
-Erik |
You are correct. I renamed them to power supply boards, as they can be considered a power supply board if the large caps are installed.
Soon. I will be offering the option of purchasing the kit with the snubber component instead.
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Brian |
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| BrianGT |
The new LM3875 rev.3 boards shipped out to me from the board vendor today. I should expect them by the mid/end of next week.
I will be out of town this weekend, leaving Saturday morning and returning on Monday (unexpected family issues), and I will also be out of town next week from Wednesday to Saturday morning (business trip), but I will get the new kits put together and shipped as soon as possible.
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Brian |
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| jazzbearz |
| waiting for snubberized 3875 kit. a question. it seems like a lot of people using just a pot for volume control. does the circuit has enough gain to deliver loud sound? don't have preamp so.... Thanks. |
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| BrianGT |
| quote: | Originally posted by jazzbearz
waiting for snubberized 3875 kit. a question. it seems like a lot of people using just a pot for volume control. does the circuit has enough gain to deliver loud sound? don't have preamp so.... Thanks. |
I will offer the snubberized kit soon.
As for the gain, it is higher than a normal amp, 33.45, vs traditional 20, so you should be able to get enough volume out of the amp without a preamp.
As for the boards, I forgot that I ordered 2nd day shipping, so they will be here on Monday.
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Brian |
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| e.lectronick |
I just looked at your site, Peter. Are these the boards available on your order form, yet? Or are those the rev B listed there?
-Erik. |
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| Peter Daniel |
I picked those boards from a manufacturing house yesterday (local place in Toronto), and they can be ordered directly from here: http://www.audiosector.com/lm3875.shtml (item 3875-PCB-P, for the board only, or as a part of a premium kit, which I'm also selling). Those are gold plated, with clear mask and black screening.
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| peranders |
| The pcb's look real nice! :up: :nod: |
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| andy2667 |
Hello Peter,
Why you said Zobel components are not recommended for the Premium 3875 kit in your web page?
Andy |
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| Peter Daniel |
| The Premium kit is intended for the very best sound quality (from a chip amp). It's offered with a best combination of parts (that I'm aware of) to realize full potential of that circuit. If your speakers do not create problem (for the amp), both Zobel and snubber take away what well implemented chip is all about: the sound becomes colored and manipulated, less airy and lively, microdetail, texture and snap of the bass is lost and the amp becomes more "average", although some may say it's more pleasing. Of course, it may not be compatible with all speakers, and in some setups, unfortunately, Zobel may be required, or snubber preferred. But neither of them is an upgrade to the amp. |
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| jackinnj |
| quote: | Originally posted by Peter Daniel
The Premium kit is intended for the best possible sound quality (from a chip amp). It's offered with a best combination of parts (that I'm aware of) to realize full potential of that circuit. If your speakers do not create problem (for the amp), both Zobel and snubber take away what well implemented chip is all about : the sound becomes colored and manipulated, less airy and lively, microdetail, texture and snap of the bass is lost and the amp becomes more "average", although some may say it's more pleasing. Of course, it may not be compatible with all speakers, and in some setups, unfortunately, Zobel may be required, or snubber preferred. But neither of them is an upgrade to the amp. |
Could you demonstrate any or all of the above? |
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| Peter Daniel |
| Yes, I can demonstrate that, but we have to meet to make that posible. |
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| Peter Daniel |
| quote: | Originally posted by Peter Daniel
The Premium kit is intended for the very best sound quality (from a chip amp). It's offered with a best combination of parts (that I'm aware of) to realize full potential of that circuit. |
I understand that some of you may be picky about wording here, so I will rephrase it. It is not a claim that this combination is the best. It' just that presently I, myself, cannot improve on it. YMMV. |
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| jackinnj |
| nah, we don't have to meet (I'll show you mine if you show me yours!) I would just like to see how the REV C kit works at 20, 25,32, 56, 77 and 100kHz at the rated output without a compensation network. |
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| Peter Daniel |
| Well, it may not work, and it may be a trade off, but I'm choosing lesser evil. |
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| homer09 |
Hey Brian,
Just wondering if there is any news with the Rev3 LM3875 boards. Havent heard much said about them here since about a week ago when you said they were arriving within a day or two...
Thanks. |
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| macboy |
| quote: | | I picked those boards from a manufacturing house yesterday (local place in Toronto), ... gold plated, with clear mask and black screening. |
Very nice looking boards. Where in Toronto did you have them made? I have been looking for a reasonably priced Canadian PCB house for some of my own board designs. |
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| BrianGT |
| quote: | Originally posted by homer09
Hey Brian,
Just wondering if there is any news with the Rev3 LM3875 boards. Havent heard much said about them here since about a week ago when you said they were arriving within a day or two...
Thanks. |
I received them last week, and have started getting the kits together. I was out of town for most of last week (only home for 3 out of the last 10 days), but am now back in Atlanta, and will get the remaining orders shipped out this week. I will try to remember to post some pictures of the boards tonight.
The LM4780 boards will arrive today as well. (were supposed to arrive last friday, but UPS delayed it 1 day.)
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Brian |
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| BrianGT |
Here is a picture of the new rev.3 power supply board with the snubber setup:
front
back
The standoffs make it easy for mounting to the chassis, which is the reason for the slightly larger pcb.
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Brian |
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| BrianGT |
A few more pics here:
http://chipamp.com/diyaudio/
I didn't install the LED yet on the board, as I am low on them, and will be getting another shipment Friday.
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Brian |
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| jleaman |
| Brian i like how the cap's are under neeth good job. ( like alway's ) |
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| homer09 |
Pretty sleak Brian!
Any pics of amp board? |
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| BrianGT |
| quote: | Originally posted by homer09
Any pics of amp board? |
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Brian |
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| budwiser |
Brian or anyone else,
I have an avel lindberg in my GC currently hooked up to the old style PS board. The wires are as follows: Blk 0v to ac2H,,, Ora 0v to ac1H,,, Red 25v to ac ac2N and finally Yel 25v to ac1N.... I bought the upgrade PS and would like to know how to make the correct connections as on the new PS board there is an ac1 (w/ line over it) and ac1 (without line over it) an ac2 (with line) and ac2 (without line). Is the designation on the old supply of H and N meaning Hot and Neutral? If so which on the new PS board would equate.
Thanks.
Pete |
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| BrianGT |
| quote: | Originally posted by budwiser
Brian or anyone else,
I have an avel lindberg in my GC currently hooked up to the old style PS board. The wires are as follows: Blk 0v to ac2H,,, Ora 0v to ac1H,,, Red 25v to ac ac2N and finally Yel 25v to ac1N.... I bought the upgrade PS and would like to know how to make the correct connections as on the new PS board there is an ac1 (w/ line over it) and ac1 (without line over it) an ac2 (with line) and ac2 (without line). Is the designation on the old supply of H and N meaning Hot and Neutral? If so which on the new PS board would equate.
Thanks.
Pete |
Pete, for the new notation, AC = H, and AC(with bar) = N. I did this to try to make it more clear (it was Peter's idea, and I like it).
Note that the two "H" windings are in the middle of the board now.
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Brian |
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| budwiser |
Brian,
Thanks to the clairification. Great work on the boards. I am plling out the old PS tonight and inserting the new one after I make my changes to the amp boards. I have been using the GC for about 5 month now and I love it. It replaced my McIntosh 2105/Hafler 220 combo.
Pete |
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| budwiser |
Brian,
My GC works just fine but something I noticed with other people using the Avel trans is that they have the wires that are marked 0v going to the ac1 and 2 N and the other 25v going to ac1 and ac2 H. Is it a problem that mine is opposite. My 0v wires go to the H connections and 25v to the N.
Pete |
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| BrianGT |
| quote: | Originally posted by budwiser
Brian,
My GC works just fine but something I noticed with other people using the Avel trans is that they have the wires that are marked 0v going to the ac1 and 2 N and the other 25v going to ac1 and ac2 H. Is it a problem that mine is opposite. My 0v wires go to the H connections and 25v to the N.
Pete |
The polarity of the wiring isn't too important, as long as you keep the same polarity notation for each of the windings. (AC is non-polar, but I like to match the polarity in wiring up the primary and secondary windings with respect to the AC hot coming from the wall)
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Brian |
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| ex192 |
How long is the delivery time to Germany for orders under audiosector.com?
(premium kit)
Any reply would be great. Thank you. |
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| ransom peek |
Have purchased the Rev C Briangt kit (not snubberized).
Where to start? There is no manual.
On Brians site there is:
Rev C board layout with parts list and positioning
Manual for previous rev
I havent seen any photos of rev C 3875 units, although the ones on brians site are not typically identified, so could be any variety...
Is there a schematic for this somewhere? The one on brians site is for the snubberized version. Any other information to absorb before beginning the build?
Ransom Peek |
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| Evilsizer |
| quote: | Originally posted by ransom peek
Have purchased the Rev C Briangt kit (not snubberized).
Where to start? There is no manual.
On Brians site there is:
Rev C board layout with parts list and positioning
Manual for previous rev
I havent seen any photos of rev C 3875 units, although the ones on brians site are not typically identified, so could be any variety...
Is there a schematic for this somewhere? The one on brians site is for the snubberized version. Any other information to absorb before beginning the build?
Ransom Peek |
as of feb. 15th the rev c manual is up.... |
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| ransom peek |
No, the manual posted is for previous revisions. There is a separate note with pcb board diagram and rev C parts list, and a schematic for snubberized version.
So, for standard version, rev C, do we use the old manual and the pcb layout and parts list and sort it out with that?
Ransom Peek
http://www.chipamp.com/lm3875.shtml |
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