Some measurements. Comparison of the Pearl Two "front end" with supplied JFETs on the stock boards vis a vis OPA2604 run at the top of the permissible voltages. Gain is identical for each, and each preamplifier is loaded resistively with 6k8:
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Thank you Lajozs.
Here are three fotos of my drawings for the boards, maybee they can be to some help. They are seen from the component side. When I do my circuitboards I make a copy of my drawing and tape it on the component side of the of the board. I drill through and after som work whith the sharp cupperedges round the hole whith a handheld drill, some cleaning and a few gentle whipes whith steel wool I handpaint the cuppertrases whith a special pen. Then I ets the boards and they are ready for soldering!
By the way I also have bult some other Passamps. 20W from the -70's, ZEN mk2, B1 and F5 turbo.
Here are three fotos of my drawings for the boards, maybee they can be to some help. They are seen from the component side. When I do my circuitboards I make a copy of my drawing and tape it on the component side of the of the board. I drill through and after som work whith the sharp cupperedges round the hole whith a handheld drill, some cleaning and a few gentle whipes whith steel wool I handpaint the cuppertrases whith a special pen. Then I ets the boards and they are ready for soldering!
By the way I also have bult some other Passamps. 20W from the -70's, ZEN mk2, B1 and F5 turbo.
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@Abrandt:
Thanks for the attachements!
Nice stereo job on such a little piece of PCB (your figures attested by the number of squares
). Unfortunately, my special pen (used last time in '90s) has dried up long ago. My last circuits were made with an engraving handtool: not very comfortable, ugly a bit - but efficient...
Thanks for the attachements!
Nice stereo job on such a little piece of PCB (your figures attested by the number of squares
). Unfortunately, my special pen (used last time in '90s) has dried up long ago. My last circuits were made with an engraving handtool: not very comfortable, ugly a bit - but efficient...
Thank you Wayne and Nelson, for your never ending support of us DIYers! Even without being able to build all of your designs, I had so many great nights reading and discussing these designs I lost count! Luckily BoSoZ kept me company all this time .
Now that Toshiba has ended the production of the 2SK370/2SK170 families of JFETs, they are getting rather rare. On a Dutch forum we try to build at least 10 Pearl two's but locating a supplier who can deliver like 150+ devices is a little difficult. 150+ to be able to match and have some spare seems allmost undoable. Without reading all the pages on this brilliant site so far, is there a good replacement for these JFETs?
.Now that Toshiba has ended the production of the 2SK370/2SK170 families of JFETs, they are getting rather rare. On a Dutch forum we try to build at least 10 Pearl two's but locating a supplier who can deliver like 150+ devices is a little difficult. 150+ to be able to match and have some spare seems allmost undoable. Without reading all the pages on this brilliant site so far, is there a good replacement for these JFETs?
Trial Run!
First impression - where was that bass before?
Second impression - dead quiet even with no chassis spaghetti wiring!
Third impression - my tube phono pre sure added coloration
Fourth impression - more detail
I think I'll keep it!
I also had to do a little creative component placement as my NOS ERO caps that I used in the RIAA filter were a touch bigger than the WIMA.
First impression - where was that bass before?
Second impression - dead quiet even with no chassis spaghetti wiring!
Third impression - my tube phono pre sure added coloration
Fourth impression - more detail
I think I'll keep it!
I also had to do a little creative component placement as my NOS ERO caps that I used in the RIAA filter were a touch bigger than the WIMA.
Attachments
Nice... Isn't it?
Box it up and call it done!
... And I see you buy the best interconnects in the world also. Well done.
VERY NICE! Good synergy across the line-up (all NP) also. Love BJC!
Faceplates are at the machine shop for a logo, LED holes and an LCD screen on the preamp. I'll post completed pics also with all the pretty lined-up blue power LEDs on the faceplates.
Use Spencer @ FETAudio ... reasonable prices, matched devices and fast shipping. Oh, and NO FAKES!