Personally I would want the extra headroom with the 24V secondaries. Because the amp is really best suited for 8ohm loads. So voltage headroom will be desirable. That said, 22V would work fine too.
So Russ says he would prefer to have a 24VAC toroid but that 22VAC would be fine to.
I suppose I could ask John at Antek about the option to have a discount on how much we buy rather than how many we buy that way we could get either 24 or 22 based on what people wanted. We will see. Give me and Peter a day or so to get it sorted.
Uriah
I suppose I could ask John at Antek about the option to have a discount on how much we buy rather than how many we buy that way we could get either 24 or 22 based on what people wanted. We will see. Give me and Peter a day or so to get it sorted.
Uriah
My Bad!
I did a little looking around on the original thread, and I think my previous reference was regarding a straight chip amp with the LM3886 only, and 4 Ohm speakers.
Sorry.
John
I did a little looking around on the original thread, and I think my previous reference was regarding a straight chip amp with the LM3886 only, and 4 Ohm speakers.
Sorry.
John
I am back from vacation and am willing to bundle a
package for this project and will work on this as soon
as I'm caught up...
Being a one man operation is not as easy as it used to be.
I do have all the items needed to finish this project
and will look into a project box too.
I will notify on this thread if I can find a suitable chassis
Steve @ Apex Jr.
package for this project and will work on this as soon
as I'm caught up...
Being a one man operation is not as easy as it used to be.
I do have all the items needed to finish this project
and will look into a project box too.
I will notify on this thread if I can find a suitable chassis
Steve @ Apex Jr.
Peter, Uriah, Russ and Brian-
Am I correct in the PCB size being:
Board size w/o heatsink (from earlier post):
4.115" from back of LM3886 to front, 3.27" wide,
2" high (2.5" incl. standoffs).
I got that off of a post on the Twisted Pair forum (Thanks guys for keeping the legacy product support up on the site!)
Am I correct in the PCB size being:
Board size w/o heatsink (from earlier post):
4.115" from back of LM3886 to front, 3.27" wide,
2" high (2.5" incl. standoffs).
I got that off of a post on the Twisted Pair forum (Thanks guys for keeping the legacy product support up on the site!)
(Welcome home Steve, now back to work!!! )
Yes I know, The joys of a one man operation..
Steve @ Apex Jr.
Yes I know, The joys of a one man operation..
Steve @ Apex Jr.
Troy,
I think you are about right. Mine is 1.8 inches tall and about a tenth of an inch shorter in length than you said.
Uriah
Welcome back Steve. Hope it was a relaxing vacation.
I think you are about right. Mine is 1.8 inches tall and about a tenth of an inch shorter in length than you said.
Uriah
Welcome back Steve. Hope it was a relaxing vacation.
Vacation was COLD, I went to see my daughter graduate
with her masters from Met university in London and then
to Croatia and Bosina...
Cold, hailing and no one open...
Steve @ Apex Jr
PS......... Am Glad I got some time off.
with her masters from Met university in London and then
to Croatia and Bosina...
Cold, hailing and no one open...
Steve @ Apex Jr
PS......... Am Glad I got some time off.
I thought that Antek only made transformers with 24V secondaries in 10 and 600VA?? http://www.antekinc.com/trans.html To get VA ratings between those you have to go with either 22 or 25V secondaries....unless he'd be willing to make some cusomt ones for our group buy, but then again, that'd probably push the cost up to the point of making it..well...pointless
Yeah, I am using his 600VA right now. I Figure it leaves room to grow and its not much more expensive than a few VA less. I was concerned about turn on thump but the circuit takes care of that and I have no turn on thump. Love it!
Uriah
Uriah
I think I killed my RevC tonight. I built it in Feb '07 and used it to run some Niles speakers from my computer. I also populated a Kookabura but never hooked it up. Last week, lightning took out my living room receiver.
Time to finish the Kookabura ! I used the Avel 15v + 15v that came with the kit but was unsure of how to connect it. I ran one 15v output to each side of the AC pins on the pcb and summed (barrier strip) the two 0v grounds to the center pin AC on the pcb. To power the transformer I plugged the blue (-) and grey (115v) into the same holes in the barrier strip as I was using to power the cheepo gold Parts Express trafo on my RevC.
At first it worked but the volume pot was scratchy. I fixed a cold solder joint on the pot and powered up again. One channel lost 90% power and sounded tinny and the static and popping was still in the pot. One sink was warm, always cool before the Kookabura. Then I lost the other channel. I took the Kookabura out of the circuit and wired the RevC the way I used to have it. Still dead.
Can it be saved ? My post @ Twisted Pair , this was my first amp project.
Time to finish the Kookabura ! I used the Avel 15v + 15v that came with the kit but was unsure of how to connect it. I ran one 15v output to each side of the AC pins on the pcb and summed (barrier strip) the two 0v grounds to the center pin AC on the pcb. To power the transformer I plugged the blue (-) and grey (115v) into the same holes in the barrier strip as I was using to power the cheepo gold Parts Express trafo on my RevC.
At first it worked but the volume pot was scratchy. I fixed a cold solder joint on the pot and powered up again. One channel lost 90% power and sounded tinny and the static and popping was still in the pot. One sink was warm, always cool before the Kookabura. Then I lost the other channel. I took the Kookabura out of the circuit and wired the RevC the way I used to have it. Still dead.
Can it be saved ? My post @ Twisted Pair , this was my first amp project.
question
can I replace the LM318 with something like NE5532 or NE5534
or TL072 .
cus I cant get LM318 in my area and cant order it .
can I replace the LM318 with something like NE5532 or NE5534
or TL072 .
cus I cant get LM318 in my area and cant order it .
Re: question
I would not try it without changing a few things. It is possible, but I would not suggest it for a beginner.
I am sure you can source the part somewhere. 🙂
funky2x said:
I would not try it without changing a few things. It is possible, but I would not suggest it for a beginner.
I am sure you can source the part somewhere. 🙂
squalor said:
You basiclaly wired the tranformer secondaries in parallel(getting you a single 15V secondary) instead of series (getting you 30V with a center tap). When you wire a pair a secondaires in series the point at which you join them becomes a ceneter tap. That is what should have been connected to GND.
I am not sure what all is dead. But I would start checking the VREGs. On the RevC I would look at the protection cct and the LM318.
Beyond that advice, I am not sure I can think of much to tell you, except I am very sorry for your bad luck...
Cheers!
Russ
Since I was in such a state of confusion during all this, I feel the skills needed to repair the RevC are beyond me. I also feel the need to own a Carver preAmp.
I propose a offer to any honest chip amp guru here with a big parts drawer. If you repair my RevC I will give you my Kookabura, Darwin and 15v trafo.
I propose a offer to any honest chip amp guru here with a big parts drawer. If you repair my RevC I will give you my Kookabura, Darwin and 15v trafo.
What improvements could I expect...
What improvements could I expect from this approach over the design offered by chipamp.com?
I really know nothing technically, but I can follow directions and solder. I have put together a number of tube amps and will be finishing my chipamp LM3886 dual mono amp over the holiday.
I've seen that there is a group by for this design that I might consider, but I am curious if I will get significant sonic benefits from this design over the one I am currently building.
What improvements could I expect from this approach over the design offered by chipamp.com?
I really know nothing technically, but I can follow directions and solder. I have put together a number of tube amps and will be finishing my chipamp LM3886 dual mono amp over the holiday.
I've seen that there is a group by for this design that I might consider, but I am curious if I will get significant sonic benefits from this design over the one I am currently building.
My first listen is still only on one channel. I think the vocals are much better. I would personally roll off the highs a little. This could be my speakers though. This board is great as it eliminates turn on thump and it protects speakers as well.
The group buy is closed however.
Uriah
The group buy is closed however.
Uriah