| cviller |
I'm drawing a new layout for pearl because I have some slightly different parts and I enjoy the process of reading a schematic, make the layout and etch it my self.
But since I am redoing it completely, I am trying to figure out if I should change the layout slightly.
The input section is according to the article and threads very sensitive to noise. If the two boards are in the same case, the input of one of the channels will be very close to the output and voltage regulater of the other - is that a problem? Would it be a good idea mirror the channels so the two input sections can be together or far apart?
I'm making it for someone I know and I think he will prefer, if he doesn't have to split two many cables, so Right and Left should be placed close to each other for input and output if possible.
I have made some suggestions and attached primitive sketches. What do you guys think, should I try something new or try to get as close as possible to Waynes layout? |
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| cviller |
| I forgot to explain my sketch. The gray circles indicate the input section, where noise should be minimal and the black circles are the capacitors for psu and where regulation will be placed. Right and left are indicated by red and black wires. |
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| steenoe |
Hi cviller. Alternative C on your drawing looks like a good bet.
With the boards placed in one side of the case you can run the supply leads in the opposite side, maximizing the distance between signals and supply leads. That said, my Pearl is in the same case as the trafo at the moment and its pretty silent.
Steen:) |
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| cviller |
Hi Steen,
Thank you for your comments. It is also the configuration I prefer. :cool:
I haven't started layout yet, but I think I'll start soon, because I have most of the components already. :D
Another thing I need to decide is whether I should go for single or double sided layout. I guess it should be possible to make it single sided - on the pics from the article it looks like there are only very few traces on topside. It looks like fat ground traces - is it?
Our friends :scratch: at diyzone appear to be making a kit with groundplane on top:
http://www.diyzone.net/article.php?sid=639
Does that even make any difference? Does it shield the signal traces against radiation from the components? I thought groundplanes were more useful in RF circuits... |
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| steenoe |
Yes, the topside is a groundplane with a few traces that, as far as I can recall, are groundtraces allright . Its easy enough to use a groundplane, only trouble (if making the boards yourself), is to remove the copper where the components are placed. The circuit might be simple enough for a singlesided layout, and should be doable without the groundplane also.
If you look at the online version (not the pdf) on Passdiy, there is some nice high resolution pic's.
http://www.passdiy.com/projects/pearlono4.htm
Try to click on fig. 7;) Looking forward to see your results.
Steen:) |
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| cviller |
Hi
I don't know if this is a good idea, but I'm posting a very early draft of my layout. :xeye:
I still need to clean up, make it a bit shorter and make some of the traces wider. I have decided to fill as much as possible with ground.
Comments are most welcome, but please remember that this is just a draft I made last night. :angel:
I'll post my schem too. |
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| cviller |
| ... and here it is: |
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| steenoe |
Cool idea to replace the SK389 with SK170's. Those SK389 are pretty hard to find. Nice work on that board:)
Steen:cool: |
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| cviller |
| quote: | Originally posted by steenoe
Cool idea to replace the SK389 with SK170's. Those SK389 are pretty hard to find. |
That is exactly why I did it, but I'm not completely sure how much I need to match them.
I have cleaned up the board so it should fit on a 180x80 mm board.
Any comments to my layout? |
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| Zen Mod |
| quote: | Originally posted by steenoe
Cool idea to replace the SK389 with SK170's. Those SK389 are pretty hard to find. Nice work on that board:)
Steen:cool: |
talkin' 'bout replacin'................. |
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| steenoe |
Hi Zen Mod.
I love that pic, can I use it as my avatar?:D I guess its no secret by now, that I build everything that Papa posts on Passdiy;) And a bit more! Right now I have an Aleph 5 in the oven:D The Aleph 5 is the "pet" of so many ppl, so I need to hear it for myself:) Take a look at the boards so far. BTW I heard that the Elna Duorex II are the most bang for the money, so I will check that out too!
Okay, to get back on track;) Cviller, the better you match, the better you fare! I think that the sk170's wasnt matched by Pass labs for the original Pearl Q-pack. But it would be an advantage to do so. For the last stage, (normally a sk389, that you replaced by 2 sk170's) I think it would be best to match those two.
BTW Cviller, If you turn on your email, I might have something for you;)
Steen:cool: |
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| steenoe |
| quote: | | Any comments to my layout? |
Wow:D Looks great to me allright. Any chance to see a pdf of the copperside in B/W??:) I did a complete run through your board not so long ago:D Everything seems just right!!
Steen:cool: |
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| Zen Mod |
Steen:
enjoy in new avatar :devilr:
is this good enough?
if yes -just check exact measures before printing |
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| cviller |
| quote: | Originally posted by steenoe
BTW Cviller, If you turn on your email, I might have something for you;)
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Sounds good, I think I have turned it on now. I will look forward to "something"! ;)
| quote: | Originally posted by steenoe
Wow:D Looks great to me allright. Any chance to see a pdf of the copperside in B/W??:) I did a complete run through your board not so long ago:D Everything seems just right!!
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Thank you for looking through my board - I won't post the copperside online right now, but you I can send it to you. I have to make sure that I'm not anyones toes... I know there are still some fabricated boards available. |
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| cviller |
| Oh. Zen mod is maybe a bit to fast for me... |
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| Zen Mod |
| quote: | Originally posted by cviller
Oh. Zen mod is maybe a bit to fast for me... |
hehe and I really don't care for anyone who is selling boards made on someone's other IP ;)
even if I must admit that sometimes I'm too fast ...........
just joking-if you have ready made pdfs just post it-this one is pretty rough Adobe-ized........:devilr: |
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| steenoe |
| quote: | | hehe and I really don't care for anyone who is selling boards made on someone's other IP |
And I dont think that our friend, cviller intends to do that;)
I have the coolest avatar, right now:D :D
Steen:cool: |
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| Zen Mod |
| quote: | Originally posted by steenoe
...............
I have the coolest avatar, right now:D :D
Steen:cool: |
hehe
Pass's teenager :devilr: |
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| steenoe |
He-he, yourself:D Hey Choky, I have to tell you this little secret: I am nearly done with the babblefish:cool: C'mon, I am 48, not excactly a teenager:D
Steen:cool: |
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| Zen Mod |
| quote: | Originally posted by steenoe
He-he, yourself:D Hey Choky, I have to tell you this little secret: I am nearly done with the babblefish:cool: C'mon, I am 48, not excactly a teenager:D
Steen:cool: |
regarding secret.........mebbe I have few really minor changes in Babel.....change all 0R22 to 0R33......for start you can use 4U7 in feedback path,later you can try without.......that's all from top of my head
if you are interested in good spk protection (universal type :devilr: ) just mail me
cviller-sorry for off topic.........when I meet steen or babowana........it's usually mess........ :clown: |
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| steenoe |
I had a feeling that the 0,22 was a bit on the rough side;) Hey you should see my chassis for the Babbelfish :) its way cool in the oldfashion Aleph style:cool: I will take a shot tomorrow;)
My intention was to parralel 2 fets!! I will get back to ya in the Babbelfish thread!
Steen:cool:
Sorry, Cviller for this slight disturbance!! |
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| cviller |
| quote: | Originally posted by steenoe
Sorry, Cviller for this slight disturbance!! |
No problem.
There is a small error in the posted layout R3 should have been a 2W resistor. I have corrected that and I think it should be ready for testing. So if anyone wants the copperside, just drop me an email. The layout is designed for primitive etching, so pads are all nice and large.
(The pdf on my web page is corrected)
http://viller.org/audio/pearlpcb.pdf |
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| cviller |
I changed the layout so that 2sk389 can be used. It is not too difficult to mount two 2sk170 in the footprint of a 2sk389 - harder the other way around! ;)
I have also etched the board. Too bad the developer must have been old or something, because I usually get better results. I think the boards will work anyways.
Here is a picture of one of the boards:
You can see that I had to scratch some shorts. :( |
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| steenoe |
That looks great. Nice layout, indeed. Did you tinplate the tracks?
Steen:) |
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| cviller |
Thanks! Yes, the copper is tin-plated.
I don't know if I can resist the temptation of soldering on some components today... :nownow: |
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| cviller |
Couldn't wait any longer...
I hope it is not a smoker! :xfingers:
I'm a bit concerned about those big capacitors and ~45 vdc - should I do something before I turn on the voltage? |
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| Zen Mod |
| quote: | Originally posted by cviller
Couldn't wait any longer...
...................................... |
ugly!
:devilr: |
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| cviller |
:whazzat:
The pmos Q1 in the psu was connected wrong - no smoke, but wrong voltages. I changed it and now it seems to be fine. I'll change it in the layout, if anyone want's to try to make their own board.
I have attached the schematics with the pmos flipped.
Now I just have to figure out how to test it without a turntable... |
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| steenoe |
Hi cviller, those populated boards look great. Happy to hear that the thing didnt explode:D A few bug's are to be expected.
If you measure the approx. same voltages at the points where Wayne put them in the schematic, you have all chances that the circuit works:) Please let us know how close your measurements are. The values probably wont be "bang on", but that is not of concern. As long as they are fairly close to Wayne's values, you should be fine.
Steen:) |
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| cviller |
Not all of them are within 5%, but some of the values are fairly close. I have tested all the points and written them on the schem.
W is for wayne
R and L are the two channels... guess most people in here would figure that out anyways.
The only voltages that are really off are the small ones across R25 and R28-31 - but I guess it doesn't matter too much. |
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| steenoe |
That ought to work:) If you wanted closer values across R28-R31, my guess is that matching both the J-fets and their source resistors would help a bit. Not sure it would matter a lot though.
Steen:) |
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| cviller |
| quote: | Originally posted by steenoe
That ought to work:) If you wanted closer values across R28-R31, my guess is that matching both the J-fets and their source resistors would help a bit. Not sure it would matter a lot though.
Steen:) |
I don't think that would do anything besides bringing the values closer to each others. The difference measured by Wayne is actually a greater than my measurements. His variation is 40% from a mean of 50mV and I have 12% of a mean of 121mV on the worst (R). Correct me if I'm wrong.
My higher voltages might be due to some noise, because I haven't connected the inputs to anything. If I hook up the system to my stereo, there is some noise when the inputs are not connected to something and this might generate a larger current across R28-31...
By the way you said that you would use some different capacitors - I can adjust the layout if you send me a list of those that does not fit and what the spacing should be instead.
Are the optional input capacitors (C14,16,17 on my schem) necessary for an MM pickup? Do I need to read its specifications and insert values accordingly, or can I just hear if there is something wrong? |
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| steenoe |
| quote: | | I don't think that would do anything besides bringing the values closer to each others. |
Neither do i:)
| quote: | | I can adjust the layout if you send me a list of those that does not fit and what the spacing should be instead. |
Wow thanks, thats mighty kind of you. Maybe a set of different hole spacings for each capacitor would be nice. I will do a little measuring when I get home.
| quote: | | Are the optional input capacitors (C14,16,17 on my schem) necessary for an MM pickup? |
Not necessarily.
It depends on the cartridge. The cartridge's spec-sheet will tell you.
Steen:) |
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| cviller |
| quote: | Originally posted by steenoe
Neither do i:)
Wow thanks, thats mighty kind of you. Maybe a set of different hole spacings for each capacitor would be nice. I will do a little measuring when I get home.
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No problem. The manuals are great too. :D |
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| steenoe |
| quote: | | The manuals are great too. |
Indeed:D
Legspacings of 7,5 mm and 12 mm, besides those you used allready would be great.
Steen:) |
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| cviller |
| quote: | Originally posted by steenoe
Indeed:D
Legspacings of 7,5 mm and 12 mm, besides those you used allready would be great.
Steen:) |
All capacitors except lyts and output cap have been changed to a version with 5,7.5,10,12 and 15 mm leg spacing. You can see the layout here:
http://viller.org/audio/2006nov_pearl/pearlpcb.pdf
I'll send you a pdf with copperside.
If anyone else want to do some etching I'll be happy to send pdf/ps with copperside in A4 or letter.
Too bad I have to wait until tomorrow to hear it... :bawling: |
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| steenoe |
| quote: | | I'll send you a pdf with copperside. |
Thanks a lot. The layout looks great. Time to experiment with different caps in the RIAA eq. :)
Steen:cool: |
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| cviller |
Finally got an opportunity to test my boards and I am astonished by how good it sound!!! :bigeyes:
The guy I made it for has a Marantz PM-15S1 amp with phono input and a SA-15S1 cd player. Before I made the pearl, we compared some records where he had both CD and vinyl and the vinyl version was ok, but very dull compared to the CD. After pearl, the situation is quite the opposite - first time for me to hear old records sounding better than CD's! :D
Thanks Wayne and Nelson!!! |
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| Zen Mod |
| quote: | Originally posted by cviller
All capacitors except lyts and output cap have been changed to a version with 5,7.5,10,12 and 15 mm leg spacing. You can see the layout here:
http://viller.org/audio/2006nov_pearl/pearlpcb.pdf
I'll send you a pdf with copperside.
If anyone else want to do some etching I'll be happy to send pdf/ps with copperside in A4 or letter.
Too bad I have to wait until tomorrow to hear it... :bawling: |
if you insist............
sasica5ATgmail.com
;) |
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| Zen Mod |
wow
this is fast!
:worship:
:devilr: |
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| steenoe |
| quote: | | first time for me to hear old records sounding better than CD's! |
:D
Its pretty easy to get used to a decent vinyl sound. Only drawback is that it's next to impossible to go back to CD's again;)
Steen:) |
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| cviller |
| Too young to have a vinyl collection... :bawling: |
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| Zen Mod |
I spent yesterday few hours crawling on flea market .....besides other goodies,I bring home 11 LPs for 11 euros.........even if few are duplicates for some I already have,it's nice feeling ;)
Steely.....Aya
man -I'm happy camper........... |
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| henkel |
Hi!
Would appreciate if someone can advise me.
I built a Pearl phonostage sometime back and was happy with the performance. I recently went for a passive pre-amp, and found that the Pearl does not have enough gain to drive the passive pre amp.
I have a pair of 35V 5amp toroidal transformers lying around, can I use it to power the Pearl over the recomended 30V trannies. Will 35V be too high input power for the Pearl?
Also would a higher voltage result in higher gain for the Pearl?
Thanks for looking and look forward to your guidance. |
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| cviller |
| quote: | Originally posted by henkel
Hi!
Would appreciate if someone can advise me.
I built a Pearl phonostage sometime back and was happy with the performance. I recently went for a passive pre-amp, and found that the Pearl does not have enough gain to drive the passive pre amp.
I have a pair of 35V 5amp toroidal transformers lying around, can I use it to power the Pearl over the recomended 30V trannies. Will 35V be too high input power for the Pearl?
Also would a higher voltage result in higher gain for the Pearl?
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The voltage regulation would just run hotter. If you want the gain section to run at a higher voltage, you'll have to recalculate the regulation. But I think Wayne would have already included that in his design, if it is so simple.
I'm quite sure what you need is another gain stage with a lower output impedance. |
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| lineup |
| quote: | Originally posted by cviller
I'm quite sure what you need is another gain stage with a lower output impedance. |
Bride-of-Zen
may be a nice matching preamp from Mr. Pass.
One IRF610 amplifier MOSFET
using zener shunt regulated single supply ~60Volt.
BoZ, Bride of Zen, has got rather low output impedance.
No problem driving 5kohm.
The original Gain is like x10 ( +20dB ), but could be easily modified a bit.
Only change one or two resistors to set gain.
Could you use same +- 35VDC supply???
You know this is ~70V.
===========================================
Some links:
BoZ preamp project
http://www.diyaudio.com/forums/show...?threadid=86555
Using BoZ, improved version
for 10 V RMS output driving, SEWA - Seven Watt Amplifier (buffer power amp)
http://www.diyaudio.com/forums/show...0&pagenumber=14
| quote: | Bride of Zen: by Nelson Pass
"This is the second installment of a trilogy of construction projects centered around the performance obtainable from absolutely minimalist circuitry. Part one described the Zen amplifier, a 10 watt single-ended class A power amplifier using a single MOSFET gain stage.
In this piece we will examine its pre-amplifying mate,
also a single gain stage MOSFET circuit. "
(The Audio Amateur, 4/94 by Nelson Pass)... download (301k). |
http://www.passdiy.com/legacy.htm
Download Project Theory, description, instructions and schematics:
http://www.passdiy.com/pdf/brideofzen.pdf
lineup |
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| cviller |
| quote: | Originally posted by lineup
Bride-of-Zen
may be a nice matching preamp from Mr. Pass.
One IRF610 amplifier MOSFET
using zener shunt regulated single supply ~60Volt.
BoZ, Bride of Zen, has got rather low output impedance.
No problem driving 5kohm.
The original Gain is like x10 ( +20dB ), but could be easily modified a bit.
Only change one or two resistors to set gain.
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Sounds like good suggestions! :)
Maybe I should add pins for some gain to my layout...
| quote: | Originally posted by lineup
Could you use same +- 35VDC supply???
You know this is ~70V.
[/B] |
Pearl is only running on a single + rail, so the 5 volts different wouldn't change much but some of the capacitors are rated quite close their operating point so they might not last as long. |
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| cviller |
| So what did you do? Did it work? |
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| henkel |
I did not change the trannies. I used an old trick as advice by Promithues earlier. I doubled the resistor value of R19 from 499R to 1K. That gives me 3db more, which seems o.k. for now. May want to try and half the resistor value of R27 for 47K to 22K.
Any problems with that? |
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| steenoe |
Hi Cviller. I thought it was best to continue in your own thread;) If you could squeeze in a set of holes for the outputcap with 37,5 mm dist, it would be great. The Rifa PHE 426 10uF has that dist and I would like to try it for this. I will also try some polyprop-rolls and maybe some MKT's. The pic shows a couple of couplingcaps for the output; the Rifa and a Clarity SA cap that will be testet.
To have a baseline of how bad (?) it can sound, I matched a pair of Siemens stackfoil MKT's for the RIAA eq. I know they are supposed to sound bad, but I do want to hear it for myself;) From then on I will try and climb the audio-ladder to see how much influence the caps has.
Steen:) |
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| cviller |
Looks like your components are getting ready to become a new pearl. ;)
I used some Elko bipolars - cheap but with golden letters :mafioso: so they must be good. ;)
The sound is extremely good, but I don't know if some better ones could make it even better.
I have updated the design...
http://viller.org/audio/2006nov_pearl/pearlpcb.pdf
I'll send you a B/W pdf. |
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| steenoe |
Wow, that was fast. We better watch out, the other guys might start calling us "The Dynamic Danish Duo" :clown:
I dont think the Bipolar eltrolytic is the best choice, but if you think it sounds good, why not?
Steen:) |
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| cviller |
| quote: | Originally posted by steenoe
Wow, that was fast. We better watch out, the other guys might start calling us "The Dynamic Danish Duo" :clown:
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:devilr:
| quote: |
I dont think the Bipolar eltrolytic is the best choice, but if you think it sounds good, why not?
Steen:) |
I read a test of different caps written by someone here on diyaudio and he gave some bipolars a quite good review. I don't remember who it was and I cannot find the link - maybe one of your friends can dig up the thread. ;)
I needed some stuff from a supplier who doesn't stock any MKP's so I took a chance on some of his better bipolars. The pearl is not mine anymore, so I don't think I'll test different caps, unless he thinks it would be interesting. |
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| Zen Mod |
| quote: | Originally posted by steenoe
Wow, that was fast. We better watch out, the other guys might start calling us "The Dynamic Danish Duo" :clown:
I dont think the Bipolar eltrolytic is the best choice, but if you think it sounds good, why not?
Steen:) |
hehe..........why not ..........TDDD........... :clown:
when TDSD is pretty lazy in last few months.......... |
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