So close. Power supplies work, Joshua tree seems to work. Will a different value pot alter how sensitive it is? I've had it keep opening/closing a relay without touching the pot. It also seems that the two boards track differently (?!) though they're too close together to be 100% sure at this point. This seems odd to me, so it may be that the relays have a slightly different sound every other switch and I only think it's simply coming from two different boards.
Next up is doing more wiring and actually hooking up the X-BOSOZ - if that goes cleanly (I expect it will) I'll wire it up to my X-GC and see how that works out. 🙂 Sooo close.
Of course, I have yet to figure out what kind of boxes these are going in. . . still lots of work to do.
Also had a tap break off doing the fifth hole for the X-BOSOZ in one HS, so I get to do yet another and figure out something else to do with that HS. AHh well.
C
Next up is doing more wiring and actually hooking up the X-BOSOZ - if that goes cleanly (I expect it will) I'll wire it up to my X-GC and see how that works out. 🙂 Sooo close.
Of course, I have yet to figure out what kind of boxes these are going in. . . still lots of work to do.
Also had a tap break off doing the fifth hole for the X-BOSOZ in one HS, so I get to do yet another and figure out something else to do with that HS. AHh well.
C
cjd said:
Hi C,
Well nothing can go perfectly smooth now can it? 🙂
If the wiring is OK the relay PCBs will be in exactly the same state as each other since they are being controlled in parallel from the same controller. The relays do seem to have a distinct clicking sonic signature which can make them sound a little unique. 😀
Your continual switching between two states sounds like one of two things. A fluctuating DC level on the POT which could possibly be caused by the grounding scheme(among other things). It also could be that the pot is bad, or too high a value. 5K - 10K seem to work best for me.
Can't wait to read about your results!!! 🙂
Cheers!
Russ
Pot is the supplied one (though, it looks like it took two weeks to get to me!) I have a 10k on hand I'll try.
Grounding... um... is there anything I need to do specifically about grounding? This is just the JT out on its own, not connected to any amps or anything. I have not wired in earth yet.
While I'm thinking of it, is there a preferred way to wire the transformer in for the JT? It seems the output voltage is where it needs to be on just one winding, but I'm not absolutely sure. Read through the JT thread looking for that answer... Maybe that's part of my problem? 🙂
And finally, I'll ask again... did you ever get my e-mail of a couple weeks ago (re: X-GC modular boards)? Not sure if it went through since I used the board software. . .
C
Grounding... um... is there anything I need to do specifically about grounding? This is just the JT out on its own, not connected to any amps or anything. I have not wired in earth yet.
While I'm thinking of it, is there a preferred way to wire the transformer in for the JT? It seems the output voltage is where it needs to be on just one winding, but I'm not absolutely sure. Read through the JT thread looking for that answer... Maybe that's part of my problem? 🙂
And finally, I'll ask again... did you ever get my e-mail of a couple weeks ago (re: X-GC modular boards)? Not sure if it went through since I used the board software. . .
C
Hi C,
I did get your email, and I replied. Did you get my reply? Maybe went to junk folder?
The JT controller circuit needs about 5-12VAC 5-7VAC is optimal. each relay PCB draws about 150ma so 300ma for the two.
Sometimes there is a bad pot in a batch. But it could indeed be supply related.
Also just double check there are no shorts, it could be that as one relay is switching on it is drawing enough current (due to a short) to effect the ADC by causing the rail to sag. The relay switching on and off would set up a sort of harmonic in that case.
Just things to check. I would check the power in and the pot first. Any cheap pot should work as long as it is in good working order. Linear would be preferred.
Cheers!
Russ
I did get your email, and I replied. Did you get my reply? Maybe went to junk folder?
The JT controller circuit needs about 5-12VAC 5-7VAC is optimal. each relay PCB draws about 150ma so 300ma for the two.
Sometimes there is a bad pot in a batch. But it could indeed be supply related.
Also just double check there are no shorts, it could be that as one relay is switching on it is drawing enough current (due to a short) to effect the ADC by causing the rail to sag. The relay switching on and off would set up a sort of harmonic in that case.
Just things to check. I would check the power in and the pot first. Any cheap pot should work as long as it is in good working order. Linear would be preferred.
Cheers!
Russ
Probably junk folder - the question is, on my end, or on the server! I'll dig through and try to see if I can find it.
The switching thing only happens now and again, and tapping or slightly tweaking the pot fixes it. I'll try the other I have (10k linear). I will also try each JT board separately, since I have two wired up. Since it only happens every so often, my guess is that it is pot related.
With the supplied trafo, a single winding is sufficient then? (or the pair in parallel?)
C
The switching thing only happens now and again, and tapping or slightly tweaking the pot fixes it. I'll try the other I have (10k linear). I will also try each JT board separately, since I have two wired up. Since it only happens every so often, my guess is that it is pot related.
With the supplied trafo, a single winding is sufficient then? (or the pair in parallel?)
C
cjd said:
O certainly yes, if you are using the trafo we supply for XBOSOZ one of the secondaires on the small trafo will work fine. In fact that is what I am using for the last couple months now.
I will email you again.
No, no, the supplied trafo for the JT is what I'm talking about... though, that *is* a thought to snag one of the others and limit it to two. 🙂 I measured ~10V on the supplied JT trafo, one winding...
cjd said:
AH ok, my confusion. Sorry. If it is the trafo supplied for the JT use both secondaries in parallel.
Need some help/advice here, I've developed a fault on the left channel of my BosoZ which is large amounts of hiss out of the speaker, changed over channels of source and amp, swapped over power supply and pots, changed out diodes, checked for cold solder joints and still no joy, hope its not the fets. Any help/idea's appreciated.
Cheers Bruce
Cheers Bruce
Member
Joined 2002
Assesears said:
Humm yes mine to has some hiss. I can't do any thing about it at the moment as im moving but when i move i can listen to it more closly and see what i can come up of it.
I'll be able to let you know how mine sounds shortly.
Just have to connect the source to the pre and the pre to the amp and it's ready to go!
Munching some home made something or other dessert that's delicious though, so gotta finish that first.
C
Just have to connect the source to the pre and the pre to the amp and it's ready to go!
Munching some home made something or other dessert that's delicious though, so gotta finish that first.
C
Well...
After one stupid mistake (power supply backwards, somehow, after checking it 3 times) it all works. Blew the 22uF cap pretty quickly, so hopefully no harm done beyond that. Seems to be none. Only one channel, so I'll just add another part to the order I need to place.
It's still very quiet. Changing to a source that puts out more and it picks up distortion still. So I must have something amiss in my amp circuit. I'll get the schematic to you guys soon, I've been updating it with everything.
The Joshua Tree works fine, but there is one spot that has a very distinct "pop" when one relay switches on. I haven't tried to isolate which "side" it's on, and I haven't tried the other board yet.
Otherwise, it's quiet, and very clean, when it's playing within the range where it works well. No hiss that I noticed. And a definite improvement over running the X-GC with single ended input straight in.
C
After one stupid mistake (power supply backwards, somehow, after checking it 3 times) it all works. Blew the 22uF cap pretty quickly, so hopefully no harm done beyond that. Seems to be none. Only one channel, so I'll just add another part to the order I need to place.
It's still very quiet. Changing to a source that puts out more and it picks up distortion still. So I must have something amiss in my amp circuit. I'll get the schematic to you guys soon, I've been updating it with everything.
The Joshua Tree works fine, but there is one spot that has a very distinct "pop" when one relay switches on. I haven't tried to isolate which "side" it's on, and I haven't tried the other board yet.
Otherwise, it's quiet, and very clean, when it's playing within the range where it works well. No hiss that I noticed. And a definite improvement over running the X-GC with single ended input straight in.
C
Can you destroy the fets if you try and mersure the resistens betwen the legs without the power connected?
Hi Vigo,
FETs typically are extremely sensitive to ESD. It is always wise to be very cautious about grounding yourself very well while working with them. Wearing a grounding strap while handling FETs is a good idea.
I usually just make it a habbit to put mine on when I start to work on my electronics.
I have killed a dozen or so FETs just by walking across a room getting something and touch a trace connect to the gate of a FET before grounding myself.
Cheers!
Russ
FETs typically are extremely sensitive to ESD. It is always wise to be very cautious about grounding yourself very well while working with them. Wearing a grounding strap while handling FETs is a good idea.
I usually just make it a habbit to put mine on when I start to work on my electronics.I have killed a dozen or so FETs just by walking across a room getting something and touch a trace connect to the gate of a FET before grounding myself.
Cheers!
Russ
Russ, do you have a thread or place where you're supporting the JT? I'm having definite issues... no solder problems that I've found going over it with the magnifying eye glasses.
C
C
Hi C
That thread is here:
http://www.diyaudio.com/forums/showthread.php?postid=848119#post848119
And the last few posts , may help you out.
Also note that the attenuator will give you a pop in a couple spots if there is any DC in the signal. The more DC offset the more the pop. This is actually common for switched attenuators (not just relays). The best way to eliminate it is to eliminate the DC.
It is common to forget about DC offset on the inputs of a power amp.
Cheers!
Russ
That thread is here:
http://www.diyaudio.com/forums/showthread.php?postid=848119#post848119
And the last few posts , may help you out.
Also note that the attenuator will give you a pop in a couple spots if there is any DC in the signal. The more DC offset the more the pop. This is actually common for switched attenuators (not just relays). The best way to eliminate it is to eliminate the DC.
It is common to forget about DC offset on the inputs of a power amp.
Cheers!
Russ
Ready to test Power Supplies
Russ,
I'm a raw novice at electronics and I have just soldered up my Power Supplies for the XBOSOZ kit. I have the Avel transformers. I will wire them as follows:
Positive
- outputs - red/orange shorted together,
- Yellow to AC+1,
- Black to AC+2
- 120 VAC inputs - Violet + Blue to Neutral
- Brown + Grey to Hot
Negative
- outputs - red/orange shorted together
- Yellow to AC-1
- Black to AC-2
I noticed in the post listed below in which you were illustrating how to measure the voltage on both +ve and -ve outputs, that you had two components mounted on the bottom of your ps board.
http://www.diyaudio.com/forums/showthread.php?postid=856885#post856885
What were the components, where are they mounted and what do they do?
After powering up the board, and measuring the DC voltage, do I have to short each capacitor with a resistor to unload it for safety? If so, what is the recommended resistor size?
TIA, Fred
Russ,
I'm a raw novice at electronics and I have just soldered up my Power Supplies for the XBOSOZ kit. I have the Avel transformers. I will wire them as follows:
Positive
- outputs - red/orange shorted together,
- Yellow to AC+1,
- Black to AC+2
- 120 VAC inputs - Violet + Blue to Neutral
- Brown + Grey to Hot
Negative
- outputs - red/orange shorted together
- Yellow to AC-1
- Black to AC-2
I noticed in the post listed below in which you were illustrating how to measure the voltage on both +ve and -ve outputs, that you had two components mounted on the bottom of your ps board.
http://www.diyaudio.com/forums/showthread.php?postid=856885#post856885
What were the components, where are they mounted and what do they do?
After powering up the board, and measuring the DC voltage, do I have to short each capacitor with a resistor to unload it for safety? If so, what is the recommended resistor size?
TIA, Fred
Hi Fred,
The components you see on the bottom are 10K 3W resistors between the capacitor leads. I used them to drain the capacitors during unloaded tests of the power supply for safety. When you have the power supply connected to the preamp it will always be loaded since the circuit is class A. So for normal use they are not really required, but they certainly don't hurt either. 🙂
Your transformer wiring appears correct as described. 🙂
Cheers!
Russ
The components you see on the bottom are 10K 3W resistors between the capacitor leads. I used them to drain the capacitors during unloaded tests of the power supply for safety. When you have the power supply connected to the preamp it will always be loaded since the circuit is class A. So for normal use they are not really required, but they certainly don't hurt either. 🙂
Your transformer wiring appears correct as described. 🙂
Cheers!
Russ