BTW, if you need hook up wire for the AC path, I am sure the tails of the transformer have more than enough length to help serve that purpose.
For the earth ground to the chassis, I prefer at LEAST an 18AWG solid wire. Crimped and soldered. Attached with lock washer on scaped clean aluminum (If anodized). Loctite on the nut.
But that's just me....
For the earth ground to the chassis, I prefer at LEAST an 18AWG solid wire. Crimped and soldered. Attached with lock washer on scaped clean aluminum (If anodized). Loctite on the nut.
But that's just me....
Okay Qusp, your point is valid, especially as he is a sponsor of the forum.
I'll give him a go myself once I run out of the silver-plated copper.
Wow these are some great responses. So the consensus is to stay from johns silver. Check. I never really thought of using cat5e cable as hook up wire but it makes sense as it's normally used to send data, etc. I have tons of cat5e at work. Just used it to rewire my post-production facility. Then again the belden analog audio wire we have should suffice as well. For the safety ground wire I could snag some of solid core thicker stuff we just used to redo the electrical in our audio mix room. And you're prolly right jdk -- I could most likely use the scraps from the trafo wires for power wires. So altogether I think I have what I need to finally finish this project with the exception of my case. I'm having it custom made by a gent on eBay. I shared a link earlier in the thread.
As far as ground returns go... I'm still trying to wrap my head around it. So I attach an extra wire to each terminal - tip, ring, and sleeve and go to the output ground on the amp PCB?
As far as ground returns go... I'm still trying to wrap my head around it. So I attach an extra wire to each terminal - tip, ring, and sleeve and go to the output ground on the amp PCB?
Only the sleeve terminal(s) go to the output ground(s) of the amp PCB. Tip is the left channel. Ring is the right channel.
BTW, what Qusp is suggesting is to use twisted pair wiring whereas one of the wires is the signal and the other is the ground. In this way, the ground twisted around the signal wire helps to provide noise immunity to the signal wire.
A least that is my interpretation of what he is suggesting.
A least that is my interpretation of what he is suggesting.
Thats correct Jake, thats what i'm suggesting and i'm also not suggesting just any old tinned copper or steel network cable. I suggested that model and others like it, which are solid copper in teflon, you'll find uses for it everywhere. they have it at markertek and numbers of retailers and i'm sure there are equivalents from other companies. Belden just happens to be the best that I know of.
Alternatively, since I don't have 4 pins on my 1/4" jack, I'll have to take some of that cat5e cable from work and create 3 twisted wires.
It's going to be a few weeks before I finish this amp -- going on vacation. Thanks to all who have helped thus far in my project. I'll be sure to take some pics and let everyone know how things work out.
It's going to be a few weeks before I finish this amp -- going on vacation. Thanks to all who have helped thus far in my project. I'll be sure to take some pics and let everyone know how things work out.
why would you do that? the only reason to use 3 wires instead of 4, even for a phono connector or cable is to save money, the ONLY reason.
each signal should have a return, there are 4 pads on the PCB for this reason …use them … regardless of the 1/4 only having 3 terminals, the ground terminal will be large enough to solder 2 wires to. why take 2 twisted pairs, remove a wire, skip a connection on the PCB because you only see 3 terminals?
each signal should have a return, there are 4 pads on the PCB for this reason …use them … regardless of the 1/4 only having 3 terminals, the ground terminal will be large enough to solder 2 wires to. why take 2 twisted pairs, remove a wire, skip a connection on the PCB because you only see 3 terminals?
So I want to thank everyone in this forum for helping me make building this amp possible especially jdkJake and qusp. This time around I learned about AC to DC conversion and grounding. The amp sounds really good. Thanks OPC for a great design.
This amp has got my curiosity up about trying, if I can find a BAL-BAL board, to do a portable SE-BAL amp in an altoids or other small case. So if anyone has an extra BAL-BAL please PM me. Pictures to come in the impressions, build thread.
This amp has got my curiosity up about trying, if I can find a BAL-BAL board, to do a portable SE-BAL amp in an altoids or other small case. So if anyone has an extra BAL-BAL please PM me. Pictures to come in the impressions, build thread.
Hey Gents. Finally got around to finishing up my SE-SE wire. I'm using a 50K Khozmo SMD attenuator in my build. Sonically, it's very very clean. I'm having an issue with volume level though; simply doesn't get loud enough. With Attenuator all the way up, it's at a low to medium listening level.
Thoughts? figured I'd check the l/r in pads for v - see what I'm getting from the attenuator output. Just curious if anyone else has seen this.
Thoughts? figured I'd check the l/r in pads for v - see what I'm getting from the attenuator output. Just curious if anyone else has seen this.
MrR -- I had the same issue with a 50k blue velvet. I was originally at a gain of 2. I upped the gain to 4 and it helped out considerably. I get good volume at around 3 o'clock -- compared to 12 o'clock on a CTH with the same 50k pot. I know others have used 50k pots for this amp, but not sure about their gain settings. I'd say you could either add some gain or use a 10k pot instead.
Hi, I have finally started my amp build and instantly came come up with a few problems.
On the power supply board the instructions call to mount the diodes first. Do the diodes D4/D5 - D9/D10 - D3/D2 - D8/D7 share a common pad? I cannot tell if I can bridge the legs with solder to make it easier.
I hope this question is clear enough. This is my first SMD build and I am struggling a bit.
On the power supply board the instructions call to mount the diodes first. Do the diodes D4/D5 - D9/D10 - D3/D2 - D8/D7 share a common pad? I cannot tell if I can bridge the legs with solder to make it easier.
I hope this question is clear enough. This is my first SMD build and I am struggling a bit.
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MisterRogers:
Try this:
1. Short R13 and R17
2. Remove R14 and R18.
3. Wire the output of the attenuator to the usual input.
With the way you have it now, you've got a 50k pot driving a 10k input impedance and you're going to lose some signal in that arrangement.
Also, what headphones are you driving? If it's a very low sensitivity type, then the next step would be to increase the gain of the amp by adjusting R16/20 or R15/19. Start with 2 and work your way up from there. Remember, it's best to have the volume control fully cranked at your loudest listening level. If you never go beyond 1/2 then you're throwing away signal!
null object:
One side of each diode pair shares a common connection. The side running to the caps is common. Take a look at the schematic for reference.
Feels free to bridge the solder on that side if it makes life easier for your.
Cheers,
Owen
Try this:
1. Short R13 and R17
2. Remove R14 and R18.
3. Wire the output of the attenuator to the usual input.
With the way you have it now, you've got a 50k pot driving a 10k input impedance and you're going to lose some signal in that arrangement.
Also, what headphones are you driving? If it's a very low sensitivity type, then the next step would be to increase the gain of the amp by adjusting R16/20 or R15/19. Start with 2 and work your way up from there. Remember, it's best to have the volume control fully cranked at your loudest listening level. If you never go beyond 1/2 then you're throwing away signal!
null object:
One side of each diode pair shares a common connection. The side running to the caps is common. Take a look at the schematic for reference.
Feels free to bridge the solder on that side if it makes life easier for your.
Cheers,
Owen