Peter,
Thanks for the answer. I have the resistor in place in the amps I am using right now (with my RadioShack 100k alps pot!), I was just trying to figure out what it's purpose was. After I read your message, I recalled reading something similar before. Did I miss another thread I should be reading?
Thanks again,
David
Thanks for the answer. I have the resistor in place in the amps I am using right now (with my RadioShack 100k alps pot!), I was just trying to figure out what it's purpose was. After I read your message, I recalled reading something similar before. Did I miss another thread I should be reading?
Thanks again,
David
With 100k pot, you definitely need that resistor. There were some previous posts discussing that (and not from Fred), but nothing really you might miss😉
I see no reason to put this in the trading post. What both Peter and Brian are doing are services to the chip amp community. I see no reason to take a socialist view here. Time is not free. It takes a great deal of time, effort, and personal monetary investment to get a large group buy going. In the end, it is highly unlikely that anybody who offers kits/products like this to a large number of people will have any idea whether they will make money or lose money until after it has happened. They are allowing us to get parts much cheaper than we ever could otherwise, and they deserve a fair compensation for their time, effort, and initiative. And when they donate a percentage of what profit (if any) they make, it becomes even more of a public service than a business venture.
Pointing fingers at people and accusing them of exploiting the forum for their own personal profits is not a very good way to encourage people to start group purchases. This means all of us will have to buy everything at normal, low volume prices from various distributors. A group buy like this is not an effective way to make money, and in fact, Peter will be lucky to break even. If he were to sell things for exactly what he payed, he could lose hundreds of dollars on a popular item, because there are always hidden costs people fail to take into account when planning these things. As far as I'm concerned, Peter and others can post group buy threads anywhere they want, and hopefully will continue to do so, since the rest of us benefit much more than they do.
Pointing fingers at people and accusing them of exploiting the forum for their own personal profits is not a very good way to encourage people to start group purchases. This means all of us will have to buy everything at normal, low volume prices from various distributors. A group buy like this is not an effective way to make money, and in fact, Peter will be lucky to break even. If he were to sell things for exactly what he payed, he could lose hundreds of dollars on a popular item, because there are always hidden costs people fail to take into account when planning these things. As far as I'm concerned, Peter and others can post group buy threads anywhere they want, and hopefully will continue to do so, since the rest of us benefit much more than they do.
Variac said:
Hey Peter, LOOK: I said "someday" 😉
There is also a new trend that it's so easy to create a commercial looking webpage with ordering and shopping cart, that now everyone is making one 'cause it's cool, not because they are really a business. That already caused some controversy on the MOX crossover thread.
We also have a harder time figuring out the possible profit on the case because that's not our expertise, so the comfort level is lower.
Rest assured that at this point I (and others I am sure) are convinced that you are performing a service not making profits.
But if you do start making money on things such as the Patek, you should switch to the TP IMHO
Maybe you could do a simple line drawing of the pot and resistor- Do you just parallel the resistor with the inputs and outputs of the pot? Or do you use the pot as a shunt off before or after the resistor?
The scematic at the beginning of thisthread doesn't show the pot I don't think? Is there another schematic that does?
Thanks,
MArk
There is also a new trend that it's so easy to create a commercial looking webpage with ordering and shopping cart, that now everyone is making one 'cause it's cool, not because they are really a business. That already caused some controversy on the MOX crossover thread.
We also have a harder time figuring out the possible profit on the case because that's not our expertise, so the comfort level is lower.
Rest assured that at this point I (and others I am sure) are convinced that you are performing a service not making profits.
But if you do start making money on things such as the Patek, you should switch to the TP IMHO
Maybe you could do a simple line drawing of the pot and resistor- Do you just parallel the resistor with the inputs and outputs of the pot? Or do you use the pot as a shunt off before or after the resistor?
The scematic at the beginning of thisthread doesn't show the pot I don't think? Is there another schematic that does?
Thanks,
MArk
Variac said:
While the integrated amp offer is intended as a group buy (in reality it would never take off, if enough interest wasn't expressed), it was also a very good opportunity for me to start something I was always planning on doing, something I think I'm really good at. So it is in fact free advertising of the site. I hope it doesn't bother too many people like Fred, who probably doesn't even realize that he's trying to bring down something that can be beneficial to everybody (not for him as he seldom builds something😉). A price point is a very good measure of success with any product and if it will not match expectations of both interested parties the venture will die naturally sooner or later. I don't believe in taking opportunity of the forum, that's why I will not be advertising in Trading Post. A link at the bottom of ea. of my 8,000 posts is good enough😉
Patek will not be a group buy and the price will be reflecting that.
As to the resistor shunting the pot, it is between input pin (on a pot) and ground. It sets the limit to the max input resistance, which shouldn't be more than 22k or so, otherwise excessive DC offset occurs. I just measured a 50K pot in such arrangement and the resistance is never more than 15K (when 22k resistor is used).
Newbee transformer question
I plan to build a six channel setup. I would like to use two power supplies one for two channels and one for the remaining four, that way I can power up all six channels or just two for stereo operation. I purchased a AVEL 330VA 25V+25V TOROIDAL TRANSFORMER for the two channels, will an AVEL 625VA 25V+25V TOROIDAL TRANSFORMER work for the other 4?
Thanks,
-marc
I plan to build a six channel setup. I would like to use two power supplies one for two channels and one for the remaining four, that way I can power up all six channels or just two for stereo operation. I purchased a AVEL 330VA 25V+25V TOROIDAL TRANSFORMER for the two channels, will an AVEL 625VA 25V+25V TOROIDAL TRANSFORMER work for the other 4?
Thanks,
-marc
Hey guys forget all that and enjoy my Lemon CrEme BrUlEe Tart and Petits Pains Au Chocolat. Oh I don't remember I can't share food in the web haah. 
Ppl should DIY an amp, than DIY urself some good tea time food and serive with tea. Then finally listern to their pretty amp for good. haha, guys don't beat me up bez you can't eat my stuffs haha.
P.S: I am more than welcome to share the recipe haha.
Ppl should DIY an amp, than DIY urself some good tea time food and serive with tea. Then finally listern to their pretty amp for good. haha, guys don't beat me up bez you can't eat my stuffs haha. P.S: I am more than welcome to share the recipe haha.
I greatly appreciate both Peter and Brians efferts to bring affordable DIY to me. Both have said if there was any profit made that they would forward that to the running of this web site. It takes alot of time and risk to put together a group buy as they both have done. Brian even stated that he lost money on the BG (.50) that adds up. Peter will not know until the group buy is almost complete. I priced the GC out if I where to have bought the components myself and $60 - $65 per kits is an awsome deal. I don't see a problem and the question should never have come up. Just my 2 cents. Lets get back to discussing GC's
Hey infield, the big transformer will be more than fine for 4 channels. My question would be will the power supply bd (diode bridge/cap board) handle the current? At some point you would need some heatsinks. Obviously using 2 of the boards would solve the problem. Maybe someone more knowledgable than I has an opinion.....
Mark
Mark
In Peter's chassis, I can tell you now "it worth every penny that you had spent". You can't do any better than that. For $150 you can't even get more than one of his tool which is why his chassis looks so pretty and professional. However, building something like that is not only the tools, but also the creater's mind. You can get all that for $150 without the fear of drilling an unmatched holes on the plate, or a scrach on the serface.Even through I backed off a little bit when I saw his price. I tried to build my own bez I believe that DIY is always the cheapest. However, I quickly realize dealing with metal without the tools is so difficult. I acturally need 3 hours to sand down an unaccurate re cut like 3/16 inch thick, and it still not perfect. Also the tools is more expensive. ( However, I own some tools + exp now hehe. This is the only good thing that I build a chassis.) For Brian's board, it is just pain charity to us DIYers. How can it be better than an easy solution like this PCB. He is not makeing profit either. It is more of a sharing than actural profit making. Final point, he is encouraging people to build it with a rewand and he is losing money. Do you need someone who will act like jesus to be consider his/her action as a "help"? Do you thing $60 can really make a lot of profit? Stop trying treating everyone as the same, and read it through.
P.S: I'm kinda in a rush, so plz forgive my lousy writting.
P.S: I'm kinda in a rush, so plz forgive my lousy writting.
What do you do keep a file?
"Obviously you didn't try them both in GC amp. 50k or 100k linear pot has very poor control range and is not appropriate. I'm not talking about law faking setups, as I never tried it myself. You might find lousy tracking on cheap pots, but all the better ones are not any worse in this department. I'm curious why you didn't use linear pot in HH passive preamp (if you are such a fan of those) but decided on log Alps?"
Mr. Daniels........
I am flattered that you try so hard to keep track of everything I post and are so willing to dig back to long ago to find it. I don't believe I've actually sold any pots to anyone despite making the offer and they are long gone from the surplus store to my dismay since I would love to have some more for myself. In fact I don't recall selling much of anything to anyone on the forum and have made only a few offers in the Trading Post. I know where enough of the really good parts are in surplus that I could sell something every couple of days if I wanted to. I would do it from my own website instead of hijacking this one if I ever decide to go into that line. I guess floating group buy offers would help on inventory decisions though.........
I didn't even realize you were selling pots and that was just dumb bad luck that a random shot hit the bulls eye. I don't know what is so magical about the GC that it requires different considerations for pots than any other amp with similar gain. I have bought enough pots to assure you that the tracking is not good on even some fairly expensive pots and that the taper on something like the Alps is much different from something like a TKD. BTW the Nobles are not expensive pots and can be found in lots of mid fi equipment. I really want to address the technical and sonic considerations. Any implication that your advice was based on commercial considerations was not my intent. I made a flippant remark that just happened to strike a nerve on your part. This does highlight the real possibility of advice being suspect when commercial concerns cast a shadow over the objectivity of advice on the forum. This one of many reasons that the two need to carefully kept separate if the forum is to have any credibility. It is hard enough as it is now to offer any advice without being cross examined for motives and objectivity. There are plenty of ways to sell audio equipment and parts on the Internet without dropping it in the middle of this forum, which last time I looked, was supposed to be noncommercial, except for incidental sales on the Trading Post. Is the concept of advertising and marketing that difficult to understand?
"Obviously you didn't try them both in GC amp. 50k or 100k linear pot has very poor control range and is not appropriate. I'm not talking about law faking setups, as I never tried it myself. You might find lousy tracking on cheap pots, but all the better ones are not any worse in this department. I'm curious why you didn't use linear pot in HH passive preamp (if you are such a fan of those) but decided on log Alps?"
Mr. Daniels........
I am flattered that you try so hard to keep track of everything I post and are so willing to dig back to long ago to find it. I don't believe I've actually sold any pots to anyone despite making the offer and they are long gone from the surplus store to my dismay since I would love to have some more for myself. In fact I don't recall selling much of anything to anyone on the forum and have made only a few offers in the Trading Post. I know where enough of the really good parts are in surplus that I could sell something every couple of days if I wanted to. I would do it from my own website instead of hijacking this one if I ever decide to go into that line. I guess floating group buy offers would help on inventory decisions though.........
I didn't even realize you were selling pots and that was just dumb bad luck that a random shot hit the bulls eye. I don't know what is so magical about the GC that it requires different considerations for pots than any other amp with similar gain. I have bought enough pots to assure you that the tracking is not good on even some fairly expensive pots and that the taper on something like the Alps is much different from something like a TKD. BTW the Nobles are not expensive pots and can be found in lots of mid fi equipment. I really want to address the technical and sonic considerations. Any implication that your advice was based on commercial considerations was not my intent. I made a flippant remark that just happened to strike a nerve on your part. This does highlight the real possibility of advice being suspect when commercial concerns cast a shadow over the objectivity of advice on the forum. This one of many reasons that the two need to carefully kept separate if the forum is to have any credibility. It is hard enough as it is now to offer any advice without being cross examined for motives and objectivity. There are plenty of ways to sell audio equipment and parts on the Internet without dropping it in the middle of this forum, which last time I looked, was supposed to be noncommercial, except for incidental sales on the Trading Post. Is the concept of advertising and marketing that difficult to understand?
Re: Newbee transformer question
The 625va transformer should be just fine for the 4 channels. A single power supply board should do quite a few channels, as the MUR860 diodes are rated at 8A each.
As for running the connections, the easiest way would be to use terminal blocks on the output connections, putting 2 wires in each one, for the 4 channels. You might have to solder the capacitor on the power supply board to the bottom of the pcb, to get the terminal blocks to fit properly. Another option is to solder the capacitor to bottom of the board, to the terminal block wires coming through the bottom, as it goes from +v to +pgnd.
--
Brian
(using internet at the hotel...)
infield said:
The 625va transformer should be just fine for the 4 channels. A single power supply board should do quite a few channels, as the MUR860 diodes are rated at 8A each.
As for running the connections, the easiest way would be to use terminal blocks on the output connections, putting 2 wires in each one, for the 4 channels. You might have to solder the capacitor on the power supply board to the bottom of the pcb, to get the terminal blocks to fit properly. Another option is to solder the capacitor to bottom of the board, to the terminal block wires coming through the bottom, as it goes from +v to +pgnd.
--
Brian
(using internet at the hotel...)
Brian and Variac,
You guy's are great, Thanks!!!
I'm adding terminal blocks to my parts express order.
What's a terninal block? Just kidding. 🙂
-marc
You guy's are great, Thanks!!!
I'm adding terminal blocks to my parts express order.
What's a terninal block? Just kidding. 🙂
-marc
I have NO COMPLAINTS about the current state of affairs.
Fred does, but he complains about everything- even though he stole the idea of an active crossover from Nelson 😀 😉
Speaking of Pass - doesn't he sell circuit boards aan parts kits?
He's referred to them online too. Better go get him Fred.
Nothin more irritating than doing a group buy effort and have people complain about your motives.
Brian is beyond reproach- as I have mentioned I'm afraid he will burn out and we won't have his great resource available.
I hadn't thought that it might be inappropriate to mention commercial ventures on the Trading Post. It that's the case the we really need a place for suppliers to post their URL's and a quick description of what they offer. When people mentioned advertising, I assumed that they meant small display ads.
A list would be a benefit to us. I won't post again on this subject....
Fred does, but he complains about everything- even though he stole the idea of an active crossover from Nelson 😀 😉
Speaking of Pass - doesn't he sell circuit boards aan parts kits?
He's referred to them online too. Better go get him Fred.
Nothin more irritating than doing a group buy effort and have people complain about your motives.
Brian is beyond reproach- as I have mentioned I'm afraid he will burn out and we won't have his great resource available.
I hadn't thought that it might be inappropriate to mention commercial ventures on the Trading Post. It that's the case the we really need a place for suppliers to post their URL's and a quick description of what they offer. When people mentioned advertising, I assumed that they meant small display ads.
A list would be a benefit to us. I won't post again on this subject....
Variac said:
I shouldn't burn out anytime soon. I am enjoying this group order a lot. Once I start seeing a bunch of completed amplifiers with the kits, I will feel content that my efforts were worth it.
I put up my users guide on my new domain, BrianGT.com. I haven't created a website yet, as I have been beyond busy with other things.
http://www.BrianGT.com
Larger, high resolution pictures from the manual can be found here:
http://brian.darg.net/gallery/nigc-kit
I will be adding a bunch of material to the manual, and had intended for it to be more complete before posting it, but since the kits are already out there, I decided to post the incomplete manual.
--
Brian
Re: What do you do keep a file?
I don't keep track and file. I just entered cermet into Trading Post search and came up with your pots. The reason I remembered it is because just few days after your post, selling those pots, somebody else on a forum provided a link to a surplus place selling them for a buck or so.
I happened to go through 120 Nobel mono pots (log) as I was matching them for Audio Zone Amp-1. I was surprised with tracking precision on those pots and I had no problem with matching them to better than 0.5 dB. Those were mono pots with 31 detented position. That maching accuracy was achieved for pairs, on ea. consequent position. So please refrain from commenting on something you don't have slightes clue about.
The ones I'm selling with a chassis will be purchased from Percy Audio, and they are simply a courtesy offering, to people who don't want to place additional order and pay extra shipping.
BTW, Alps blue velvet pots can be seen in Naim top preamp (more than 10K price tag), and I noticed Nobles in BAT preamps. That's not exactly mid-fi equipment.
Fred Dieckmann said:
I don't keep track and file. I just entered cermet into Trading Post search and came up with your pots. The reason I remembered it is because just few days after your post, selling those pots, somebody else on a forum provided a link to a surplus place selling them for a buck or so.
I happened to go through 120 Nobel mono pots (log) as I was matching them for Audio Zone Amp-1. I was surprised with tracking precision on those pots and I had no problem with matching them to better than 0.5 dB. Those were mono pots with 31 detented position. That maching accuracy was achieved for pairs, on ea. consequent position. So please refrain from commenting on something you don't have slightes clue about.
The ones I'm selling with a chassis will be purchased from Percy Audio, and they are simply a courtesy offering, to people who don't want to place additional order and pay extra shipping.
BTW, Alps blue velvet pots can be seen in Naim top preamp (more than 10K price tag), and I noticed Nobles in BAT preamps. That's not exactly mid-fi equipment.
Got my boards today via Bas Horneman. They look very good, even better than expected by looking at the posted pictures. Love at first sight ... One Pana FC 1500 uF was dented from transport however so I will use 4 x 2200 uF/50V instead as I stock those in small amounts.
For my own peace of mind I will solder a Zobel network across the output terminals and a cap directly from V+ to V- at the PCB as oscillation is my enemy 😉
If there is any enjoy your honeymoon, Brian !
For my own peace of mind I will solder a Zobel network across the output terminals and a cap directly from V+ to V- at the PCB as oscillation is my enemy 😉
If there is any enjoy your honeymoon, Brian !
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