Jason-
I guess we are all a little too eager with these kits. Have you already ordered parts for the 4cap kits? If not, let's figure out the price difference and see if people would be will to pay the difference, then we can all get the new boarsa and kits. Hopefully the price difference won't be too great. One alternative would be to use the new boards and only use 4 caps. Who knows.
Brian, will the price of the new boards be higher? I think I already paid for the boards too, but I actually am starting to get confused about what I have paid for (building 4 amps at the same time is most confusing).
I guess we are all a little too eager with these kits. Have you already ordered parts for the 4cap kits? If not, let's figure out the price difference and see if people would be will to pay the difference, then we can all get the new boarsa and kits. Hopefully the price difference won't be too great. One alternative would be to use the new boards and only use 4 caps. Who knows.
Brian, will the price of the new boards be higher? I think I already paid for the boards too, but I actually am starting to get confused about what I have paid for (building 4 amps at the same time is most confusing).
Re: 4-pin caps
The older caps still work. The newer caps offer higher capacitance.
The only drawback to the new caps is the size. The Panasonic TS-UP caps are offered in a lower profile, which wouldn't really be an advantage to the Aleph designs, since the heatsinks will have to be relatively large anyway, making the chassis profile relatively tall.
--
Brian
Still accepting Aleph PCB orders:
http://www.chipamp.com/aleph
PS board poll
http://www.briangt.com/gallery/PS-poll
RKH said:
The older caps still work. The newer caps offer higher capacitance.
The only drawback to the new caps is the size. The Panasonic TS-UP caps are offered in a lower profile, which wouldn't really be an advantage to the Aleph designs, since the heatsinks will have to be relatively large anyway, making the chassis profile relatively tall.
--
Brian
Still accepting Aleph PCB orders:
http://www.chipamp.com/aleph
PS board poll
http://www.briangt.com/gallery/PS-poll
On a side note, I ordered the pcbs today, 3 oz copper, blue soldermask, 0.093" fr4, with a 2 week leadtime. Hopefully they will ship sooner (AC has been good with this and often ships a few days early). This means that in 2 weeks, I will have the boards in my hands.
I went with the larger 6 capacitor power supply board, and will post pictures/info tonight on the final layout.
I ordered extra pcbs, so I am still accepting orders:
http://www.chipamp.com/aleph
--
Brian
I went with the larger 6 capacitor power supply board, and will post pictures/info tonight on the final layout.
I ordered extra pcbs, so I am still accepting orders:
http://www.chipamp.com/aleph
--
Brian
Im helping my friend build an aleph 5 with these boards. this question was asked before, not sure if it got answered. By setting the board up for aleph 30, is it just a matter of raising the rail voltage to achieve aleph 5 status. looking at a30, the schematic for the input stage (esp around diff pair)is slightly different, everything else seems to be the same, except for a few different values, a5 with higher input impedance
what changes if any would be needed to make a5.
john
what changes if any would be needed to make a5.
john
Its basically the same. Source resistors for A5 are 1R, A30 has .47R. 3 fets for output and 3 for ccs for both. i know the input is a bit different for the A30 which results in a higher impedance for single ended input (i think). i studied the schematics but im a bit new at this
thank you
John
thank you
John
If you are in Newington, i reccomend you go down to the Berlin TPK and go to Cables and Connectors. Pick up a 10A CALRAD?current meter( they are $17.99 each) to measure bias current. Put one in series with one of the rails coming off the power supply and you can measure bias current. I'm in Farmington, and i did this was my Aleph 2's so i could easily monitor bias current. Boy does it make things easier. You might also want to consider starting w/ pots for ac current gain and bias so that you can set those to your liking. For my aleph 2's those were r21 and r19 respectively.
I doubt this answers your question exactly, but it may help overall.
-Matthew K. Olson
I doubt this answers your question exactly, but it may help overall.
-Matthew K. Olson
i Pick up a 10A CALRAD?current meter( they are $17.99 each) to measure bias current. Put one in series with one of the rails coming off the power supply and you can measure bias current. I'm in Farmington, and i did this was my Aleph 2's so i could easily monitor bias current. Boy does it make things easier. You might also want to consider starting w/ pots for ac current gain and bias so that you can set those to your liking. For my aleph 2's those were r21 and r19 respectively.
Hi Matthew, that does sound like a nice trick for biasing R19 w/ the chassis amp meter, especially because I "believe" I was reading in a search that it takes awhile for the current to reach its maximum point (maybe thats' why some people say their Alephs sound best after warming up for an hour. I couldn't find it at cables and connectore (web site) but I believe this is it?
http://www.arcade-electronics.com/cgi-bin/webc.exe/st_prod.html?p_prodid=19393
You could take it out when your done or whatever. This "30" is my first Aleph and I have been reading on the biasing quite a bit, I've got R19 (DC bias) figuered and R21 (AC gain) figuered at least mentally but I was wondering about R16? Can't seem to find to much info in searches and I have noticed that it was one of the key resistors in Brians BOM that indicated an adjustment might be necessary after biasing (?). Any thots?
Best - Stan
Hi Matthew, that does sound like a nice trick for biasing R19 w/ the chassis amp meter, especially because I "believe" I was reading in a search that it takes awhile for the current to reach its maximum point (maybe thats' why some people say their Alephs sound best after warming up for an hour. I couldn't find it at cables and connectore (web site) but I believe this is it?
http://www.arcade-electronics.com/cgi-bin/webc.exe/st_prod.html?p_prodid=19393
You could take it out when your done or whatever. This "30" is my first Aleph and I have been reading on the biasing quite a bit, I've got R19 (DC bias) figuered and R21 (AC gain) figuered at least mentally but I was wondering about R16? Can't seem to find to much info in searches and I have noticed that it was one of the key resistors in Brians BOM that indicated an adjustment might be necessary after biasing (?). Any thots?
Best - Stan
Thats the one. Leave it in. Put it in the back of the amp. Its not terrible looking, but i didn't find it worthy of the front of the amp. The amp i have does not bias slowly. I turn it on, immediately bias goes right to 4A/rail and stays. I like having a meter built into the amp. Peace of mind kind-of-a-thing
-Matthew K. Olson
I like having a meter built into the amp. Peace of mind kind-of-a-thing-Matthew K. Olson
Banned
Joined 2002
Jason,
Per what Matt said, could you include a pot (for extra fee) that would fit the board as part of the kit so that we're able to adjust the bias to our liking? For A30, I'm not sure which is the bias resistor though. From my recollection, 200K pot is good to start with.
Matt,
Do you happen to have the address of Berlin TPK? Do they do mail order?
Per what Matt said, could you include a pot (for extra fee) that would fit the board as part of the kit so that we're able to adjust the bias to our liking? For A30, I'm not sure which is the bias resistor though. From my recollection, 200K pot is good to start with.
Matt,
Do you happen to have the address of Berlin TPK? Do they do mail order?
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