Re: Baby GC is born (first one, more to come 🙂
May I ask why you double up'd the Cat 5 wires? Is it because they are such high gauge?
brentw said:
May I ask why you double up'd the Cat 5 wires? Is it because they are such high gauge?
The short answer is to increase the gage.
My cat5e recipe is based on this recipe
http://www.venhaus1.com/diycatfivecables.html
There is lots of detail on the subject in that link.
But you will find that following that recipe exactly is too much work. I tried his recipe and after 10 hours I was only 1/3 done. At that point I had a cable that had 1/3 the gage of the cable in the recipe.
In my recipe I keep the outer jacket on the cat5 wire.
I biwire my speakers. I use 3 braided cables for the treble and 3 braided cables for the bass. I pulled the xo out of the speakers and have it close to the amp, so in the picture you only see the cat5 wire that goes to the xo from the amp. If you look close at the last picture on this page
http://qlogics.com/audio/gc/first/
you will see some braided cable going to a speaker.
Using cat5 wire is the "Gainclone" of speaker cable in my opinion.
I can go on and on about it, I am such a believer in it. What a difference it made for me. More then is should (like a gainclone). I was using zip cord before. You can't beat the price of cat5 cables. You just need to invest some time making them.
It does take some time to break in. Compared to standard heavy gage zip cord you should notice a difference right away. But the highs may be a little harsh at first. Plus there will be stuff in the sound you will be wondering about, that will be music you were missing before 🙂
Use it for a week or two and then try switching back to your old speaker cables. The difference should be huge.
Cat5 recipe should not be used for long runs, or so I have read, fact or fiction, don't know until you try.
I have it working with my gainclone with no problems. I read that gainclones wouldn't like cat5 but it works great for me, thank God 🙂
By the way... I didn't use $$$ plenum (Teflon insulation) wire. It may sound even better, not that I find fault with what I have. I will try it one day or keep my eyes open for someone's comparison.
My cat5e recipe is based on this recipe
http://www.venhaus1.com/diycatfivecables.html
There is lots of detail on the subject in that link.
But you will find that following that recipe exactly is too much work. I tried his recipe and after 10 hours I was only 1/3 done. At that point I had a cable that had 1/3 the gage of the cable in the recipe.
In my recipe I keep the outer jacket on the cat5 wire.
I biwire my speakers. I use 3 braided cables for the treble and 3 braided cables for the bass. I pulled the xo out of the speakers and have it close to the amp, so in the picture you only see the cat5 wire that goes to the xo from the amp. If you look close at the last picture on this page
http://qlogics.com/audio/gc/first/
you will see some braided cable going to a speaker.
Using cat5 wire is the "Gainclone" of speaker cable in my opinion.
I can go on and on about it, I am such a believer in it. What a difference it made for me. More then is should (like a gainclone). I was using zip cord before. You can't beat the price of cat5 cables. You just need to invest some time making them.
It does take some time to break in. Compared to standard heavy gage zip cord you should notice a difference right away. But the highs may be a little harsh at first. Plus there will be stuff in the sound you will be wondering about, that will be music you were missing before 🙂
Use it for a week or two and then try switching back to your old speaker cables. The difference should be huge.
Cat5 recipe should not be used for long runs, or so I have read, fact or fiction, don't know until you try.
I have it working with my gainclone with no problems. I read that gainclones wouldn't like cat5 but it works great for me, thank God 🙂
By the way... I didn't use $$$ plenum (Teflon insulation) wire. It may sound even better, not that I find fault with what I have. I will try it one day or keep my eyes open for someone's comparison.
brentw said:
Try just a single pair of wires (ie strands) for each run (ie 4 wires total)-- best if you separate the pairs (ie cloud of wires).
dave
Really nobody who knows the distortion figures of the LM3875 chips at various input voltages. It is just that the selection of a powersupply seems really tricky to me, since I am only interrested in as clean a signal as possible, and does that mean 18V, 22V or something entirely different? VA has nothing to do with the distortion of the chip right?
Hey Meat,
I like the case better as you are using it - as a power amp.
Looks great!
BUT, we both need one LED on the front.......
If you get hum, maybe keep the input wires away from the transformer.
I like the case better as you are using it - as a power amp.
Looks great!
BUT, we both need one LED on the front.......
If you get hum, maybe keep the input wires away from the transformer.
Nuuk said:could you elaborate please?
The opposite of tidy... each strand taking its own route with varying separation (which should on average be fairly large) from the other wires. Most often seen with magnet wire.
dave
Variac said:
Thanks, I need a switch also. I will probably get a machinist to cut a nice hole for a switch. An LED would look nice also.
I used shielded input wires, but I know that laying the wire on the transformer is not the smartest. I haven't heard any hum yet though.
What's the best, most effective way to implement a Zobel with Brian's PCBs?
Is it best to just run a wire from underneath the PCB Out to the 2.7 Resistor, solder that to the 0.1uf Cap, and run a wire from the cap to OG from the bottom of the PCB?
Is it best to just run a wire from underneath the PCB Out to the 2.7 Resistor, solder that to the 0.1uf Cap, and run a wire from the cap to OG from the bottom of the PCB?
TaaJ said:
Hi,
If you have the latest version of Brian's PCB then it's simple, the holes are already there. See my clone: The green resistor and the blue 100nF cap are the Zobel.
Maarten
An externally hosted image should be here but it was not working when we last tested it.
Here a picture of my monoblocks based on Brian's boards and my favourite boxes. Together with the pre-amp (OPA627 buffer and input selector) the family is complete now.
And inside it looks like this:
Maarten
PS. Project description on gainclone page
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
And inside it looks like this:
An externally hosted image should be here but it was not working when we last tested it.
Maarten
PS. Project description on gainclone page
Nuuk said:
Thanks for your kind words Nuuk. Unfortunately I do not have your woodwork skills so I'll have to do with standard alu boxes of Conrad.
Maarten
PS. With two last pictures:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Hey Maarten-
Very nice.
I like the idea of an "extra" set of contacts on the input selector for LED's too. I will keep that in mind on my next project.
If I had those cases available here I would have saved a LOT of time and would not needed to have had mine built.
Thanks,
Troy
Very nice.
I like the idea of an "extra" set of contacts on the input selector for LED's too. I will keep that in mind on my next project.
If I had those cases available here I would have saved a LOT of time and would not needed to have had mine built.
Thanks,
Troy
. For a moment I thought I was done 
platenspeler,
I see you used the BrianGT boards by keeping the rectifier PC board attached to the amplifier PC board .
I find that very interesting. I have a set of Brian's boards running now a wood board to get everything tested and working. Sounds great! But I was having noise problems initially
I have the same implementation you do with the rectifier boards attached to the amplifier boards. I originally had the inputs connected with some teflon coated Cat5 cable wire that I had and I was getting quite a bit of noise at the output. It was not 60Hz hum but higher so I figured I was getting 120 Hz noise from the Diodes. I got rid of it by using sheilded cable to the inouts and grounding the sheild. So I figured that the attached board approach would just not work with unsheilded wire unless I separated the rectifier board from the amp board. Looks like it works for you though.
Perhaps since your run is short it works or perhaps I had some other issue. My wire was about 8" long at the time and I do get quite a bit of RF where I live. So you have no noise problems?
I see you used the BrianGT boards by keeping the rectifier PC board attached to the amplifier PC board .
I find that very interesting. I have a set of Brian's boards running now a wood board to get everything tested and working. Sounds great! But I was having noise problems initially
I have the same implementation you do with the rectifier boards attached to the amplifier boards. I originally had the inputs connected with some teflon coated Cat5 cable wire that I had and I was getting quite a bit of noise at the output. It was not 60Hz hum but higher so I figured I was getting 120 Hz noise from the Diodes. I got rid of it by using sheilded cable to the inouts and grounding the sheild. So I figured that the attached board approach would just not work with unsheilded wire unless I separated the rectifier board from the amp board. Looks like it works for you though.
Perhaps since your run is short it works or perhaps I had some other issue. My wire was about 8" long at the time and I do get quite a bit of RF where I live. So you have no noise problems?
Maarten, not only brilliant looking amps, but also briliant pics too. That's always a good thing 😉
I hope your amps aren't getting too wet on that bench though 😀
I hope your amps aren't getting too wet on that bench though 😀
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