All boards are gone no new ones are planned within a near future..
The tripots can of course be subsituted with a resistor.
Howeverthe reason for the trimpot is to easy trim the voltage coming from the PSU part.
Thanx
/JZ
The tripots can of course be subsituted with a resistor.
Howeverthe reason for the trimpot is to easy trim the voltage coming from the PSU part.
Thanx
/JZ
gabanyayaya
I understand what you meen now and No. You can not omit the pots just because you have a 15V tranny.
You still have to use them to trim the voltage.
/JZ
I understand what you meen now and No. You can not omit the pots just because you have a 15V tranny.
You still have to use them to trim the voltage.
/JZ
zei said:
I see now.........just now you said the pot can be substitute by a resistor. What values??? Is there's any different using this resistor compared to trimpot in term of SQ...? Do you think using a resistor is an alternative way to complete the power supply section without using a multi meter/volt tester?
gabanyayaya said:
Hi Gabanyayaya
You can use the following voltage calculator to help you determine the correct resistors
http://www.justblair.co.uk/lm317-voltage-calculator.html
(A shameless plug for Blair's website)
Regards
Richard
Tripmaster said:
Wow...this sure is helpful. Thanks Tripmaster. Funny though because I used to talk each other with Mr. Blair few months ago but not about chipamp but a speaker modding and I did what he told me about my speaker...😉
Can any of you geniuses out there (a few regular posters spring to mind) give me a definitive answer as to whether this board has any DC blocking on it.
I had a problem with mine at the weekend and when testing/playing with it, it blew an old speaker! A strange noise and then....phut!
I had a problem with mine at the weekend and when testing/playing with it, it blew an old speaker! A strange noise and then....phut!
You have put the caps on the output?
That should take of most junk.
So it sounds like there is something else that is the cause..
Can we have a picture perhaps? 🙂
Lets start with that.. oh and also what poweramp are you using.?
/JZ
That should take of most junk.
So it sounds like there is something else that is the cause..
Can we have a picture perhaps? 🙂
Lets start with that.. oh and also what poweramp are you using.?
/JZ
zei said:
I put all the components on the board and left none off. Is that what you mean?
For testing purposes I used a Chipamp.com LM3886 amp.
Yes, that,s was what i mean 🙂
So can we have a picture maybe of the whole thing? 😎
Don,t be shy.. 🙂
/JZ
So can we have a picture maybe of the whole thing? 😎
Don,t be shy.. 🙂
/JZ
Puffin said:Managed to massage the board into an existing remote controlled pre-amp built some years ago.
It was here all the time😉
Aargh.. of course.. sry 🙂
Ok so it is a bit tight in that box but did you try the preamp without that remote controlled thingie..?
When does the "symptom" occurs?
/JZ
Ok so it is a bit tight in that box but did you try the preamp without that remote controlled thingie..?
When does the "symptom" occurs?
/JZ
It's only a passive 20k Alps pot with a motor on it.
I had a problem with mine at the weekend and when testing/playing with it, it blew an old speaker! A strange noise and then....phut!
I had a problem with mine at the weekend and when testing/playing with it, it blew an old speaker! A strange noise and then....phut!
Strange.
It is an simple preamp with few parts so there are not many things you could check.. Is the supply generating a stady + - V ?
Besides that, how is the solderjoints?
Can you (or did you already..) go over the solderblobs again to make shure they are fine....
Did it ever work ok?
Did you place the pot on the input or output?
/JZ
It is an simple preamp with few parts so there are not many things you could check.. Is the supply generating a stady + - V ?
Besides that, how is the solderjoints?
Can you (or did you already..) go over the solderblobs again to make shure they are fine....
Did it ever work ok?
Did you place the pot on the input or output?
/JZ
The power supply is a steady + & - 15v. I will thoroughly check the solder joints with a magnifying glass.
Phono signal in to SOAP, output of SOAP to pot, then output of pot to phono outs
However you have not said whether there is any DC blocking on the PCB?
Have you ever measured any DC on this board?
Phono signal in to SOAP, output of SOAP to pot, then output of pot to phono outs
However you have not said whether there is any DC blocking on the PCB?
Have you ever measured any DC on this board?
gabanyayaya said:
Hey, Get back in touch anytime, cant remember what you did with the speaker, I might fair better if I work out your real name (email) how did you get on?
gabanyayaya said:
I can confirm, the calculator works for the 337, and also the negative varients as well.
Sorry to hear your preamps puzzling you puffin.
Oh and thanks for the shameless plug trip!
Ok, the Cap on the output should take care of any DC, And i also think you have a cap on the inout of that poweramp?
You are supposed to have the pot on the input of the preamp.
It works with the pot on the output but i think it can create a somewhat strange load for the poweramp.
I have run mine for a long time withoute any funny stuff. And no, i have,nt messured any DC on the output. thats no garantie ofcourse.
But to be shure on what happened. You just played some music and then poff? one channel dead? Or did it happened when you powered it up?
What was it that made you test/play with it? what kind of trouble?
Yea, check the solderjoints and also reheat them if possible.
/JZ
You are supposed to have the pot on the input of the preamp.
It works with the pot on the output but i think it can create a somewhat strange load for the poweramp.
I have run mine for a long time withoute any funny stuff. And no, i have,nt messured any DC on the output. thats no garantie ofcourse.
But to be shure on what happened. You just played some music and then poff? one channel dead? Or did it happened when you powered it up?
What was it that made you test/play with it? what kind of trouble?
Yea, check the solderjoints and also reheat them if possible.
/JZ