for the power supply board, i have 2 extra parts: a capacitor and a resistor. (both the capacitor and resistor seem to go with the led part of the board)
did you guys accidentally pack these extra parts? or do they go somewhere that is not marked on the board?
the resistor is a different value, so i'm figuring maybe brian put the extra led resistor in so i can change the brightness of the led...
the extra capacitor is the same value of the one i put in next to the led, so i don't know why i have this extra part.
thanks for the resistor values for the opamp board.
i know there are many posts on this, but i haven't found a really good CHEAP DIY book shelf speaker post. (around 200 dollars would be great)
anyone can recommend one?
did you guys accidentally pack these extra parts? or do they go somewhere that is not marked on the board?
the resistor is a different value, so i'm figuring maybe brian put the extra led resistor in so i can change the brightness of the led...
the extra capacitor is the same value of the one i put in next to the led, so i don't know why i have this extra part.
thanks for the resistor values for the opamp board.
i know there are many posts on this, but i haven't found a really good CHEAP DIY book shelf speaker post. (around 200 dollars would be great)
anyone can recommend one?
since an LED is basically a diode, did you make sure the longer lead (the positive end) went to the positive side of the diode?
i thought there was a picture of a diode on the board where the led supposed to go
- ---|>--- +
^
|
so longer lead goes here.
i believe i put my led orientation of the longer lead away from the capacitors (from your description:: opposite orientation of how you put it)
i could be wrong though.
i thought there was a picture of a diode on the board where the led supposed to go
- ---|>--- +
^
|
so longer lead goes here.
i believe i put my led orientation of the longer lead away from the capacitors (from your description:: opposite orientation of how you put it)
i could be wrong though.
frdchang said:
1. The extra parts: 1 cap, jus extra, 1 resistor to change the brightness of the LED. So you can decide what you want.
2. As for book shelf: The best bargin brands are: Athena AS-B1 or B2's or Titan Atoms or Engery. All these wil come under about $200. I just bought a pair of JBL at etronics for $140 free shipping. I get them tomarrow:
http://www.etronics.com/product.asp?stk_code=jble30&store=&catid=4154
Good deal.
Heh, when I was first installing the LED I wasn't sure about the polarity so I looked at this site. I installed the LED on the board with the anode at the beginning of the silk-screen triangle and the cathode at the pointed end (like in the first picture of that site). I just realized that doesn't make any sense because that would put the capacitor and resistor AFTER the LED, not before it. Long story short, the LED was backward. 
Anyway, this is the wrong thread to be discussing this.
frdchang said:
I really like this speaker. Wins now and then in the low cost DIY gatherings. Targeted to be under $100 in parts (before shipping). The upgraded tweeter is well worth the extra cost.
http://home.new.rr.com/zaph/audio/audio-speaker13.html
Not really a bookshelf as such but is a small 2 way. The port is on back and likes to be out from the wall a bit. Putting a rectangular slot port on the front at the bottom is a way around that.
email me or start a thread in the loadspeaker forum if you want more info.
Thanks for replies guys,
Is A1 Electronics posting them on the website? There are lots of Hammon transformers there and a step-up/down tranformer section. I wasn't able to find any Plitron's that you've mentioned. I guess I'll call them up and ask about it.
I am looking right now at 182P22 225VA 22V model you've mentioned. It's $51.20US... plus shipping.. I will definitely save on brokerage fee that I'd have to pay when buying recommended 330VA tranformer from US, but isn't $20-$30 that Peter suggested is a bit cheaper?
Peter Daniel said:
Is A1 Electronics posting them on the website? There are lots of Hammon transformers there and a step-up/down tranformer section. I wasn't able to find any Plitron's that you've mentioned. I guess I'll call them up and ask about it.
homer09 said:
I am looking right now at 182P22 225VA 22V model you've mentioned. It's $51.20US... plus shipping.. I will definitely save on brokerage fee that I'd have to pay when buying recommended 330VA tranformer from US, but isn't $20-$30 that Peter suggested is a bit cheaper?
Thanks,
I've ment to post the website (www.a1parts.com).
If you check out the links on the left, there's a Hammond Tranformers link. If you CTRL+F it, that's the second occurence of 'hammond' on their website. THey are not turoidal, at least the ones I saw. How should I choose one?
Thank you
I've ment to post the website (www.a1parts.com).
If you check out the links on the left, there's a Hammond Tranformers link. If you CTRL+F it, that's the second occurence of 'hammond' on their website. THey are not turoidal, at least the ones I saw. How should I choose one?
Thank you
lomtik said:
Yes ive been there the other day, and i was unable to find Hammond's toroidal series (182). The site is quite poorly designed and finding a transformer from there almost impossible unless you know exactly what you are looking for. I emailed A1 asking if they had hammond toroidals or Piltrons in surplus as Peter suggested but received no reply. Since your from toronto, why dont you call them and post their response here?
RE TRansformer at A1
there were a number of RS transformers 100VA DUAL 25v
at A1 I got one for 10$ as it was unpriced. I don't know if one could get the same price.
I made a 3875 amp using lm318 regulator and it worked very well.
with my inefficient speakers and playing loud the Xfrmer got quite warm but not hot, I would guess 105 deg F, I could easily hold my fingers on it.
One could use 2 of them, to get quite a decent PS. Perhaps one could get a group buy as there were quite a few of them.
there were a number of RS transformers 100VA DUAL 25v
at A1 I got one for 10$ as it was unpriced. I don't know if one could get the same price.
I made a 3875 amp using lm318 regulator and it worked very well.
with my inefficient speakers and playing loud the Xfrmer got quite warm but not hot, I would guess 105 deg F, I could easily hold my fingers on it.
One could use 2 of them, to get quite a decent PS. Perhaps one could get a group buy as there were quite a few of them.
My GC... well sort of....
Ok the circuit is finished..... its sounds great.
Ok the circuit is finished..... its sounds great.
An externally hosted image should be here but it was not working when we last tested it.
transformers
question. i have ordered the dual mono kit and was wondering about transformers.
It seems that 60v (2x30) is pretty good for this amp so 44v CT is about right. i was looking at 60V CT at first but it is right at the max for 3886 (60x 1.4 makes 84v) and my speakers are average about 7 ohms and dip below 4
2x 44v CT 120VA toroid $83.20
2X 44V CT 160VA toroid $92.80
1X 44V CT 225VA toroid $51.20
1x 48V CT 500VA toroid $75.20
they dont have 44V toroid in any higher VA. maybe i would like a 44V CT at 300 VA but they only have 30 and 60v ones
they are all hammonds. from parts connexion, because i can get em quite easilly.
Does it really make any difference if both channels are from the same transformer, even though they are using seperate power supplies? or is it better just to have one beefy transformer.
I dont have any "magic ears" but i can tell my other brianGT sounds better than a "100w" yamaha natuaral sound amp my friend has, and my kenwood home theater thingy. my other brianGT is 3875 uses single transformer (ILP160VA), single PSU (with bridge rectifier) and a sort of mutated "snubbersization" (1 set of big caps and snubber at PSU and small caps by each amp board)
this particular amp will be used at reasonable volume but might have to play quite loud sometimes without pooping out . speakers are mid to low efficiancy atm but may soon be changed to completely different setup.
regards
question. i have ordered the dual mono kit and was wondering about transformers.
It seems that 60v (2x30) is pretty good for this amp so 44v CT is about right. i was looking at 60V CT at first but it is right at the max for 3886 (60x 1.4 makes 84v) and my speakers are average about 7 ohms and dip below 4
2x 44v CT 120VA toroid $83.20
2X 44V CT 160VA toroid $92.80
1X 44V CT 225VA toroid $51.20
1x 48V CT 500VA toroid $75.20
they dont have 44V toroid in any higher VA. maybe i would like a 44V CT at 300 VA but they only have 30 and 60v ones
they are all hammonds. from parts connexion, because i can get em quite easilly.
Does it really make any difference if both channels are from the same transformer, even though they are using seperate power supplies? or is it better just to have one beefy transformer.
I dont have any "magic ears" but i can tell my other brianGT sounds better than a "100w" yamaha natuaral sound amp my friend has, and my kenwood home theater thingy. my other brianGT is 3875 uses single transformer (ILP160VA), single PSU (with bridge rectifier) and a sort of mutated "snubbersization" (1 set of big caps and snubber at PSU and small caps by each amp board)
this particular amp will be used at reasonable volume but might have to play quite loud sometimes without pooping out . speakers are mid to low efficiancy atm but may soon be changed to completely different setup.
regards
Re: My GC... well sort of....
I love aligator clips, when are you going to put it in a chassis?
neutron7, I'm pretty sure the power ratings are very similar to the 3875s. What I understand is they are a little more flexable with loads. I'd suggest the 1X 44V CT 225VA toroid $51.20. That will save you some money it looks like too.
You will love the sound of the lows in that amp. On my Denon I have the bass + 12db, I swear the 3886 with the snubber is about + 6db or so.
Lets see all these finished Gainclones
Josh
llmobll said:
I love aligator clips, when are you going to put it in a chassis?
neutron7, I'm pretty sure the power ratings are very similar to the 3875s. What I understand is they are a little more flexable with loads. I'd suggest the 1X 44V CT 225VA toroid $51.20. That will save you some money it looks like too.
You will love the sound of the lows in that amp. On my Denon I have the bass + 12db, I swear the 3886 with the snubber is about + 6db or so.
Lets see all these finished Gainclones
Josh
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