Hi Richard, I dd get your cheque when I got back yesterday and I have my computer up and runnig agin now, so hopefuly my responses will be a bit quiker to most requests now. I have included a list of all the orders that I will be putting through on Saturday, so it would be nice if those who havent payed yet could get in touch (Al, I still havent heard from you, so if you want to give me a ring to sort things out, give me a call on 07748 533918 and I should be able to sort something out with you then).
But, even if the payment for all of the boards doesn't reach me by Saturday, I'll still get all of them for the people who have asked, and just keep the others here with me untill people get ound to sending me the money, so it still saves a bit on the postage.
If anyone else has anyting they do want to ask about the order though, just post here or send me a mail and I should get back to you pretty quickly:
andrew.
jonclancy, UK, qty: 4 ,(1.1?) PAYED
Bigparsnip, UK, qty: 4 PAYED (Me)
f.k.l.chan, UK, qty: 4
SineEra?, Uk, Qty:4 PAYED
D3, UK, QTY: 4 PAYED
pinkmouse, UK, Qty: 6
A Titmus, UK, Qty: 6 PAYED (?)
Total: 26
But, even if the payment for all of the boards doesn't reach me by Saturday, I'll still get all of them for the people who have asked, and just keep the others here with me untill people get ound to sending me the money, so it still saves a bit on the postage.
If anyone else has anyting they do want to ask about the order though, just post here or send me a mail and I should get back to you pretty quickly:
andrew.
jonclancy, UK, qty: 4 ,(1.1?) PAYED
Bigparsnip, UK, qty: 4 PAYED (Me)
f.k.l.chan, UK, qty: 4
SineEra?, Uk, Qty:4 PAYED
D3, UK, QTY: 4 PAYED
pinkmouse, UK, Qty: 6
A Titmus, UK, Qty: 6 PAYED (?)
Total: 26
hi bigparsnip,
i think you missed my last email, i sent you another email just before, please check your mail.
or you can send me the total and your paypal account to my email directly, my email is fkl_chan@hotmail.com
sorry again for my late.
Leo
i think you missed my last email, i sent you another email just before, please check your mail.
or you can send me the total and your paypal account to my email directly, my email is fkl_chan@hotmail.com
sorry again for my late.
Leo
Right, I have finaly sent off confiramtion of the order to Chad, so hopefully everyting will be ok there and I should recieve the boards in early Febuary, so I guess all we have to do now is wait a while (unless people want to try and go any further with trying to get any heatsinks as a group).
IF anyone has any questions though, please feel free to get in touch whaenever you want, but if not, I will get back to you all closer to the time to get your address and stuff.
Andrew.
IF anyone has any questions though, please feel free to get in touch whaenever you want, but if not, I will get back to you all closer to the time to get your address and stuff.
Andrew.
Further group orders
Hi, I think it would be really good to pool resources with regard to purchasing critical components.........
Mosfets.............we obviously need quite a few! so we may be able to order part of a batch which would give excellent matching
......perhaps one of the more technically minded would be willing to match them into sets????
Capacitors ........really good audio grade capacitors are expensive..especially the larger values.
Coils
Transformers....I believe Andrew can source 600va trorroids...
Heatsinks
Is there a difinitive 'stuffing' parts list for the amp???
I would appreciate it if all uk Aleph X builders would voice an opinion........I think this is a great opertunity.
What does everybody think???
Hi, I think it would be really good to pool resources with regard to purchasing critical components.........
Mosfets.............we obviously need quite a few! so we may be able to order part of a batch which would give excellent matching
......perhaps one of the more technically minded would be willing to match them into sets????
Capacitors ........really good audio grade capacitors are expensive..especially the larger values.
Coils
Transformers....I believe Andrew can source 600va trorroids...
Heatsinks
Is there a difinitive 'stuffing' parts list for the amp???
I would appreciate it if all uk Aleph X builders would voice an opinion........I think this is a great opertunity.
What does everybody think???
Right, with regards to some of the parts, The 600VA toroids That I can get hold of wouldn't be too flexible in terms of secondary voltages I'm affraid as they would be comming from work (only dual 30 or 40, unless you drop down to 300VA where I can get 15, 18 and 25 as well). However, as long as I don't quit my job any time soon, I should be able to get hold of these any time people want for around £30 and £23 respectively (however, the postage may be quite a lot on these, so they might not work out quite a cheep as you would fist think).
As for mosfets, Does anyone know any where they may be able to source these from at a reasonable price, or failing that there are always the free samples from onsemi, which I think do an IRF240 type part.
As for heatsinks, I think looking about, for me, I would have to get some from Conrad Heatsinks in Australia, as having contacted Julian there, it looks quite possible to order only four of the 0.21deg/w MF35 151.1 heatsinks and they would only cost around £25 each.
For capacitors, unless anyone comes up with any other (cheeper) ideas, I personaly, would probably be building capacitor banks up from 63V, 6800uF Samwha audio grade caps that you can get for amplin, as these are only £4 if you order over 25 of them.
And finaly, yes there is the stufifng list for the parts, along with the circuit scheematic, whihc I have attached below, as I'm not too sure I want to go off looking for it right now.
As for mosfets, Does anyone know any where they may be able to source these from at a reasonable price, or failing that there are always the free samples from onsemi, which I think do an IRF240 type part.
As for heatsinks, I think looking about, for me, I would have to get some from Conrad Heatsinks in Australia, as having contacted Julian there, it looks quite possible to order only four of the 0.21deg/w MF35 151.1 heatsinks and they would only cost around £25 each.
For capacitors, unless anyone comes up with any other (cheeper) ideas, I personaly, would probably be building capacitor banks up from 63V, 6800uF Samwha audio grade caps that you can get for amplin, as these are only £4 if you order over 25 of them.
And finaly, yes there is the stufifng list for the parts, along with the circuit scheematic, whihc I have attached below, as I'm not too sure I want to go off looking for it right now.
After a bit more searching, I have found what might be some better caps (depending on the rail voltage you want to run at) for this project. They are Sparuge 36D types, rated at 30V and 36000uF (107mm tall and 77mm diameter) and I have found them ofr the seemingly silly price of about £7.00 each.
So, if people are interested in these, they might be a good place to start (they should still allow a good 35w of output from each channel if you have a stiff enough supply).
So, if people are interested in these, they might be a good place to start (they should still allow a good 35w of output from each channel if you have a stiff enough supply).
After a bit more diging about, I have found that the IRFP044 MOSFETS are rather pricy in the UK (RS want about £3 a go for them), however, I have seen them for as littel as $1.20 from some US suppliers. The only problem is that they won't ship outside the US or canada, and have a minimum order of $100. So, it looks like unless we can coordinate a group buy through a helpful member on the other side of the atlantic these may prove a littel on the expensive side.
Also, regarding the coments I have made above, and the transformer and capacitor specs:
Using the 30V capacitors (with the maximum rail voltage of 30V) you would be able to get closer to 100W of output, as I was forgetting the x acts as a bridge type amp when it comes to output power.
And as far as the Transformers go, only the 300VA 15V one would come close to offering much of a sensible option for building an amp. As, with the higher voltage ones, you would be strugling to get teh correct amount of curent needed from them for 8ohm opperation, nevermind if you were to set teh bias for a 4 or 2 ohm speaker. Doh!
So, does anyone have any nice american (or canadian) relatives or friends who might be able to sort out getting the MOSFETS for us? Or does anyone else know of any other suitable source?
Andrew.
Also, regarding the coments I have made above, and the transformer and capacitor specs:
Using the 30V capacitors (with the maximum rail voltage of 30V) you would be able to get closer to 100W of output, as I was forgetting the x acts as a bridge type amp when it comes to output power.
And as far as the Transformers go, only the 300VA 15V one would come close to offering much of a sensible option for building an amp. As, with the higher voltage ones, you would be strugling to get teh correct amount of curent needed from them for 8ohm opperation, nevermind if you were to set teh bias for a 4 or 2 ohm speaker. Doh!
So, does anyone have any nice american (or canadian) relatives or friends who might be able to sort out getting the MOSFETS for us? Or does anyone else know of any other suitable source?
Andrew.
Sounds good, I guess I missed that one.
also, I have found something on ebay that may be of interest for people. Basicaly it is a guy who has a lot of boxes with fairly large transformers in which appear to have +/-15V secondaries rated at 13A each (as well as a single 18V, 13A section), so if you were looking to put togethere a cheep 80W version of hte x, these could be quite useful. YOu should be able to find them on teh link below for the next day or two for only £12 each!
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=2587255910&category=4661&rd=1
also, I have found something on ebay that may be of interest for people. Basicaly it is a guy who has a lot of boxes with fairly large transformers in which appear to have +/-15V secondaries rated at 13A each (as well as a single 18V, 13A section), so if you were looking to put togethere a cheep 80W version of hte x, these could be quite useful. YOu should be able to find them on teh link below for the next day or two for only £12 each!
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=2587255910&category=4661&rd=1
For the amps I intend on building, I am looking at the folowing specs:
Transformer - 15-0-15 to give approx +/- 20V rails (18-0-18 would also be ok I guess, although things may get a littel more toasty)
Bias Current - Approx 5A (Limited by Heatsinking)
Dissipation - Approx 200W (to give around a 40deg temp rise from a 0.21deg/w heatsink)
No of out put devices per chanel - 8 (to give about 25W per device)
Output Power would be about 80w into eight ohms for the 15-0-15 transformer (that would go up to about 100W for the 18V transformer) which is more than enough for my curent speakers.
edit:
I forgot to mention the rating of the transformers, I guess for the minimum needed for either of the above would be about 300-400VA, but as long as the prices are good I have no problems going higer than this.
Also, I did order some of the ones I have mentiond above from ebay as these are rated at about 400VA for the 15 volt taps, whihc should mean these are good for up to 10A bias each whihc I think is more than enough to start with for one channel. However, if you do find anything better for a good price I'm sure I could persuade myself to have a try of a couple.
Transformer - 15-0-15 to give approx +/- 20V rails (18-0-18 would also be ok I guess, although things may get a littel more toasty)
Bias Current - Approx 5A (Limited by Heatsinking)
Dissipation - Approx 200W (to give around a 40deg temp rise from a 0.21deg/w heatsink)
No of out put devices per chanel - 8 (to give about 25W per device)
Output Power would be about 80w into eight ohms for the 15-0-15 transformer (that would go up to about 100W for the 18V transformer) which is more than enough for my curent speakers.
edit:
I forgot to mention the rating of the transformers, I guess for the minimum needed for either of the above would be about 300-400VA, but as long as the prices are good I have no problems going higer than this.
Also, I did order some of the ones I have mentiond above from ebay as these are rated at about 400VA for the 15 volt taps, whihc should mean these are good for up to 10A bias each whihc I think is more than enough to start with for one channel. However, if you do find anything better for a good price I'm sure I could persuade myself to have a try of a couple.
Andrew.........
Reichelt has 12, 15 and 18 V at 330, 500 and even 800 VA. Prices are cheap at EUR 39 for 500 VA and EUR 56 for 800 VA.
Elfa has 12/15(only up to 300 VA)/18 up to 500 VA.
http://www.reichelt.de/
http://www.elfa.se/
Reichelt has 12, 15 and 18 V at 330, 500 and even 800 VA. Prices are cheap at EUR 39 for 500 VA and EUR 56 for 800 VA.
Elfa has 12/15(only up to 300 VA)/18 up to 500 VA.
http://www.reichelt.de/
http://www.elfa.se/
Tranny
Hi, I was being a bit cheeky..................I found these links on the following pass labs thread........Aleph X transformer thread.......
I am also finding it very difficult to find the transformers.....I have emailed the person who posted the thread.....maybe I can nail the location.....if I get a repy......I might also try telephoning...
I am interested in this as my son is in the army in Germany.....he could pick up part or parts for me.
I will keep you posted on this....
Hi, I was being a bit cheeky..................I found these links on the following pass labs thread........Aleph X transformer thread.......
I am also finding it very difficult to find the transformers.....I have emailed the person who posted the thread.....maybe I can nail the location.....if I get a repy......I might also try telephoning...
I am interested in this as my son is in the army in Germany.....he could pick up part or parts for me.
I will keep you posted on this....
Heatsinks
I have been in contact with a heatsink supplier.......this is the reply I have recieved..............
Further discussion today on your application I can make the following suggestion. We have PN S142 which is 400 wide 40 high, when cut to 250mm it has a thermal performance of 0.175 C/W in natural convection. Therefore when dissipating 250W it will have max temperature rise of 43.75C, to achieve a max temperature of 65C the ambient can be no higher than 22.25C. Will this be good enough? If so please advise the potential quantity and I will arrange a quotation. If not I can look at the next size up which is considerably bigger and therefore more expensive.
Please let me know how you want to proceed.
Regards
Joe Buchanan.
Area Sales Manager.
Aavid Thermalloy Ltd.
TEL : +44 (0)141 641 9860
FAX : +44 (0)141 641 9860
MOB : 07860 414 512
I am hoping that most uk members would be interesed........
please could you reply & I will get a quote......
Richard
I have been in contact with a heatsink supplier.......this is the reply I have recieved..............
Further discussion today on your application I can make the following suggestion. We have PN S142 which is 400 wide 40 high, when cut to 250mm it has a thermal performance of 0.175 C/W in natural convection. Therefore when dissipating 250W it will have max temperature rise of 43.75C, to achieve a max temperature of 65C the ambient can be no higher than 22.25C. Will this be good enough? If so please advise the potential quantity and I will arrange a quotation. If not I can look at the next size up which is considerably bigger and therefore more expensive.
Please let me know how you want to proceed.
Regards
Joe Buchanan.
Area Sales Manager.
Aavid Thermalloy Ltd.
TEL : +44 (0)141 641 9860
FAX : +44 (0)141 641 9860
MOB : 07860 414 512
I am hoping that most uk members would be interesed........
please could you reply & I will get a quote......
Richard
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