It was a 'TF" chip nevertheles, I tried it both isolated and non-isolated, even lifted from the chassis, which served as the heatsink. Result:-22V at output.
Jimbo
Jimbo
Check out this post. I have a link to a simple schematic for it.
The capacitors I ended up using I got from Digikey. The link for their datasheet is here.
I wanted to avoid using the DC off of the power supply board, just to make sure it didn't screw anything up (even though a couple of LEDs probably wouldn't have drawn that much anyways) and to simplify the wiring. I included a fuse and switch in the circuit as well. It was a nice little side project
The capacitors I ended up using I got from Digikey. The link for their datasheet is here.
I wanted to avoid using the DC off of the power supply board, just to make sure it didn't screw anything up (even though a couple of LEDs probably wouldn't have drawn that much anyways) and to simplify the wiring. I included a fuse and switch in the circuit as well. It was a nice little side project
See post http://www.diyaudio.com/forums/showthread.php?postid=399074#post399074chipco3434 said:
Be very careful with the pot so you don't create a loop through the transformer. One winding = much current
Otherwise, nice work.
Peranders said...
Do you think that feeding the primary back through the hole is a problem or could be a problem?
Also, what should i look for with a 60Hz hum when the pot is turned down? Hum goes away when the pot is turned up.
Do you think that feeding the primary back through the hole is a problem or could be a problem?
Also, what should i look for with a 60Hz hum when the pot is turned down? Hum goes away when the pot is turned up.
I had some questions regarding the secondary hookups
on the Avel Linberg toroid because the label on it said that a different pair were the high wires, than shown on the diagram in the instructions.
so I asked the person (bluebear?) that
had asked about the primery hookups, and this was his response:
Now my amp is working!!!! So everyone can help out around here
even those that are critisized for asking too basic questions!
Here's a photo of my amp- well actually it's for my son,
I renovated some old Boston Acoustics A70 speaks for him with new surrounds, and upgrade of crossover parts
Sounds very good, but I don't think the speakers are good enough for an amp review.
Still, a great sounding setup for the money- lucky kid!!
I hope I get him used to good sound to trick him into being an audiophile!
Thanks to Brian!!! I now need to buid an amp for my office, bedroom, etc... While I guess people can argue if this is the "best" amp or not, it sure is good, and for other than your main listening room it's a no-brainer..
When I get my main speakers back on line I see if it belongs in the main room too!
I'll send this photo to your website Brian.
on the Avel Linberg toroid because the label on it said that a different pair were the high wires, than shown on the diagram in the instructions.
so I asked the person (bluebear?) that
had asked about the primery hookups, and this was his response:
I took his advice because his amp is working- no smoke!!
Now my amp is working!!!! So everyone can help out around here
even those that are critisized for asking too basic questions!
Here's a photo of my amp- well actually it's for my son,
I renovated some old Boston Acoustics A70 speaks for him with new surrounds, and upgrade of crossover parts
Sounds very good, but I don't think the speakers are good enough for an amp review.
Still, a great sounding setup for the money- lucky kid!!
I hope I get him used to good sound to trick him into being an audiophile!
Thanks to Brian!!! I now need to buid an amp for my office, bedroom, etc... While I guess people can argue if this is the "best" amp or not, it sure is good, and for other than your main listening room it's a no-brainer..
When I get my main speakers back on line I see if it belongs in the main room too!
I'll send this photo to your website Brian.
Attachments
Cool!!!
Hey Variac,
Nice to see it working. I'm still a couple of steps behind you. I've got all the boards done but am plowing into the box (its too complicated!!!). I was thinking of setting up the amp to test it on a wood plank (ala Nuuk) & your post caught my eye. I have a Avel Linberg toroid (D4040: 230 VA, 25-0-25 with solid leads) with the same color primaries & secondaries. Which tranny do you have? I haven't yet hooked anything to power yet and would like to avoid smoke also! 😀
Thanks in advance,
Bret Morrow
Hey Variac,
Nice to see it working. I'm still a couple of steps behind you. I've got all the boards done but am plowing into the box (its too complicated!!!). I was thinking of setting up the amp to test it on a wood plank (ala Nuuk) & your post caught my eye. I have a Avel Linberg toroid (D4040: 230 VA, 25-0-25 with solid leads) with the same color primaries & secondaries. Which tranny do you have? I haven't yet hooked anything to power yet and would like to avoid smoke also! 😀
Thanks in advance,
Bret Morrow
Thank you for the kind words, It is very exciting to have it work right away!!! Also I would have looked pretty lame in my son's eyes if I never got it working. When he last asked when it would be done I said a week, and he asked "a real week, or a DIY week?" A DIY week is about 2 months-It's like dog years...
I have the Avel Linberg 330VA, 2x25V output. If the leads are the same color, than I can't imagine any problem if you hook it up as I did.
Yes, the trap is the box. As an architect, I've fallen into that trap a million times. I always want something cool to blow my friends away with, then it gets complicated, then I never finish.
I HAVE learned though.... this amp is for my son who is 15.
people that age never want anything too radical. So I avoided the trap by just ordering a Par box. Not flashy, but looks like an amp, and it's finished!! Actually looks better than the pics.
For MY dual transformer, model, I'm ABSOLUTely doing the wood plank approach. Even with the Par box, all the time was drilling holes, adjusting componants,
As far as the sound, I've listened a bit more, and maybe the caps are burning in, -- the bass is really special. LOTS of ability to distinguish drumhead materials, really tight and precise.
Many have commented on this, but I kept expecting the treble to be the impressive part. Mids very good and clear but realistic.
Highs a bit muted, but I think it's the speakers. The A70 Boston Acoustics used the same Seas tweeter as all the higher end models, so I expected that to be impressive, especially since I changed out crossover components.
Overall the rig does lack a bit of the "effortlessness " of some high end stuff, and maybe "air", but I suspect it's all the speakers.
Good luck
I have the Avel Linberg 330VA, 2x25V output. If the leads are the same color, than I can't imagine any problem if you hook it up as I did.
Yes, the trap is the box. As an architect, I've fallen into that trap a million times. I always want something cool to blow my friends away with, then it gets complicated, then I never finish.
I HAVE learned though.... this amp is for my son who is 15.
people that age never want anything too radical. So I avoided the trap by just ordering a Par box. Not flashy, but looks like an amp, and it's finished!! Actually looks better than the pics.
For MY dual transformer, model, I'm ABSOLUTely doing the wood plank approach. Even with the Par box, all the time was drilling holes, adjusting componants,
As far as the sound, I've listened a bit more, and maybe the caps are burning in, -- the bass is really special. LOTS of ability to distinguish drumhead materials, really tight and precise.
Many have commented on this, but I kept expecting the treble to be the impressive part. Mids very good and clear but realistic.
Highs a bit muted, but I think it's the speakers. The A70 Boston Acoustics used the same Seas tweeter as all the higher end models, so I expected that to be impressive, especially since I changed out crossover components.
Overall the rig does lack a bit of the "effortlessness " of some high end stuff, and maybe "air", but I suspect it's all the speakers.
Good luck
Peter Daniel said:
Do you mean it might sound better with Pot? 🙂 🙂
This was a joke, no recriminations please.
Anthony
My son , who is getting the amp, and is a dedicated sax player says: "Jazzz Spazzz, that's such a cool name..."
Thanks for the kind words all. It looks so spacious inside in the photo, but it was a pain to maintain the clearences I wanted.
Peter, that pot is one of the Alps from Briger. It probably isn't the best. On MINE I will use a switched atenuator 😉
Someday soon I'll trade his out for better.... It sounds so good I want to make irt better....
I'm now fully dedicated to finishing my Basszilla Platinum Edition speakers to hear what the amp REALLY sounds like....
Thanks for the kind words all. It looks so spacious inside in the photo, but it was a pain to maintain the clearences I wanted.
Peter, that pot is one of the Alps from Briger. It probably isn't the best. On MINE I will use a switched atenuator 😉
Someday soon I'll trade his out for better.... It sounds so good I want to make irt better....
I'm now fully dedicated to finishing my Basszilla Platinum Edition speakers to hear what the amp REALLY sounds like....
I was using similar Alp pots (although 2 decks only) and they sound actually very good, especially in midrange. Comparing for instance to Noble pots, I'm using now, they lack extention (and somewhat detail) in highs. It may very well be what you are missing.
Variac said:
Puzzlecoat the cone (front & back -- 2 coats on the front. dust seal the frame, use solid core hook up wire (cat 5 is a cheap source of decent wire), and brace the baffle to the back of the cabinet (there is 1 little brace IIRC, but it isn't enuff).... putting a brace behind the woofer magnet to the back is a good idea too.
Report back...
dave
Well.... the pot reference bears fruit... 😉
You will be proud of me P-10, I had already added the second brace- the place to put it is obvious. I put urethane sealant on the frame to damp it. Maybe not enough, maybe the sealant isn't the right thing, but I did put goop on the frame.
Now you guys will diss me because it isn't good enough, but I replaced the crossover cap with a Solen, and used a non inductive resistor. The woofer rolls off without any crossover whatsoever. (that's how BA did it)
I'm very pleased with the bass and midrange, in fact I have always felt that these speakers were better than my A 150 3-way models as far as pleasing to listen to, and the mods really make them great!! Maybe we are just used to a little more treble these days? Maybe I should parallel a small resistor with the 1.5 ohm one- any value ideas? I will try your other mods in the future.....
Also the 150's are in the attic. Any suggestions for them? or basically the same thing?
Hey Peter, the amp seems to get better- the bass and mids are really exceptional now . Is it the caps, or am I acclimating to them- who knows...., but thanks for sharing your mix of components- They certainly work.
My amp was supposed to be an example of a really quick, easy and cheap way to get a decent sound. Not even close- the wood plank method is the next approach for family members amps!!
You will be proud of me P-10, I had already added the second brace- the place to put it is obvious. I put urethane sealant on the frame to damp it. Maybe not enough, maybe the sealant isn't the right thing, but I did put goop on the frame.
Now you guys will diss me because it isn't good enough, but I replaced the crossover cap with a Solen, and used a non inductive resistor. The woofer rolls off without any crossover whatsoever. (that's how BA did it)
I'm very pleased with the bass and midrange, in fact I have always felt that these speakers were better than my A 150 3-way models as far as pleasing to listen to, and the mods really make them great!! Maybe we are just used to a little more treble these days? Maybe I should parallel a small resistor with the 1.5 ohm one- any value ideas? I will try your other mods in the future.....
Also the 150's are in the attic. Any suggestions for them? or basically the same thing?
Hey Peter, the amp seems to get better- the bass and mids are really exceptional now . Is it the caps, or am I acclimating to them- who knows...., but thanks for sharing your mix of components- They certainly work.
My amp was supposed to be an example of a really quick, easy and cheap way to get a decent sound. Not even close- the wood plank method is the next approach for family members amps!!
Variac said:
Yes... stiffen the mid emclosure too (can't remember if it is plastic integral to the driver or a cardboard tube...)
dave
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