integral preamp-amp solution is sight.
the concept and prototype for a wonderfull full caruso all in one amp solution is done. the amp will have the new carusopreampboards. 2 powrfull and absolutely great amps plus current meter head protection all in a box.
there is hope! haha.just picked up another 50 caruso bodies.
they go for anondizing and then after summer break 50 more on the markt!
the updated schematics and partlist is here:
schematics for PCB3.0 caruso_schema_HW3_12_2016b
partlist for PCB3.0 caruso_partslist_hw3_2016_2
as well as the caruso dummy head print. for save and easy dummyhead build.
a bundle of 2x Carusopreamp + 1x Dummy Head is available in the shop for €90.- we deduct this if you buy a caruso head!
hello. 2 new boards are ordered and will arrive within next 2 weeks.
CARUSO preamp board V2_4
i gave another round of redesign. and now there is even a optofet on the input. you can use as a MUTE switch or as a base for a cutter current high frequency limiter. more to follow.
check the pcb:
CARUSO DUMMY HEAD PCB
and finally the caruso dummy head pcb. it will be delivered for ever head i ship in the future. easy to build no hassle with cables and stuff. all on the board.
new caruso preampboard. after 3 production runs of unchanged V1.1 boards and more than 100 builds i think its time for a little board lifting.
we work on a ready to use smd version. not sure if we produce that one.
- circuit. additional diode protection for SSM2019.
- additional RIAA Encoder pre-mixer output (for non feedback heads)
- additional GND testpoint
- important caps get more space and variable size footprint
- cleaned up placement. better visible what belongs to which group
- cleand up rooting
- new preampboad will fit into 3HZ fischer 19″ rack (baugruppenträger)
- size will be:112mm x75mm. you can mount now horizontal or vertical into the rack
- Electroless nickel immersion gold
i found some old videos for feedback setup. at this time end of 2012 i reached 34dBmax. now i get 42 dB on a good setup @ 1khz.
also setup at 5kHz is possible between 6-8 dBs. we think 6 dB @5kHz is best for the moment.
first test of new batch on SAL74C.
heads can now be adjusted with 5kHz Feedback. we recommend around 6dB of Feedback for Caruso 133-142. more tests will follow.
position of serial number changed to right side.
2nd batch Nr.133-142 in production. most of them are already reserved.
we try after a very short redesign phase to pull out another series.
feedbackcoils increased from 4.7ohm to approx 9 ohm.
also a few more productions details improved.
protection card redesigned. and major software improvments.
there is now an arduino nano based protection card made. a few samples are built and under tests.
caruso head on Neumann VMS66, SAL74B Amps . No Problemo.
extended caruso tests on a neumann SAL74B (C)
at the moment there are a lots of tests done by Hervé at DK-Mastering in Paris.
The SAL74B is slightly modified with new flokason FB Amplifiers with increased Gain for the Caruso low impedance coils. All the rest is stock SAL74B.
Nr.130 is blue elox. but inside exactly the same as all other Caruso Heads.
Running at around 22dB’s of Feedback on a SAL Rack. a slight correcture on the Weiss EQ and sound is already very nice….
another caruso on a neumann system. Caruso Nr.127 on AM32b in the land where caruso was born.
caruso is installed at ameise’s presto again. we spent a whole day cutting and adjusting values. and recording samples. watch out for the sound snippets.
also an updatet caruso_preamp v1.23 schematics with lots of remarks for the values.
Quick&Dirty Test of Caruso on Neumann VG66. works great!
Caruso Nr.129/130 finished
Caruso Nr.120 is installed on Mart’s Presto 8DG. currently in oberhausen.
we did many cuts. and i can say the sound rocks now!
feedback: 28-29 dbs @ 1000 Hz. cutting amp is PAS2002.
some slight equalizing. but not yet the best. so we will be even better.
we will put some tracks online.
breaking news! first time a caruso works on a stock neumann SAL74 rack!
the rack is not in best shape yet and the FBcard is not the B-version. that means still a transformer for the Feedback input and therefore weak bass response!
also my adapter cable could be nicer. but i wanted to make a quick&dirty test.
also due to the low impedance coils of the original caruso (only 5 ohms), the SAL got not enough signal. so i could open the FBlevel to max and only reached 24.6 dBs @1kHz. i normally need 28-30 dBs of Feedback for flat response.
but results are quite nice.nice and propper signals.
-1.1 dB off at 100 Hz.
within 1 dB up to 8 khz.
then the resonance at 13 kHz. and 2dBs up to 18kHz. i say wow.
this is no adaption of SAL cards yet. just plug and play!
so a professional version comes closer! if i just adapt feedbackcoils we will get enough Feedback to go flat!
caruso 123, 126 finished.
caruso nr.122 is shipped to australia. i did quick tests with carusopreamp and bruel&kjaer (type2706 labor) amp. it was easy to get 30 dB’s of FB at main resonance. so head is flat from 20 Hz to 16 kHz. with a peak of around 4 dB’s at 7 kHz. similar to the SC99- this has to filtered out by passive RLC Network. we give more details when we had time to play around.
i simplified the partslist for caruso preamp. check caruso pre v1.22 schematics.
building new heads.some minor changes.
also stylus changing tool is available. it comes with all heads delivered from now. the ones who have the head will receive it later_
and 2 sets of attachment. 18mm round or neumann 8 degree bar 9mm thick.
the 18mm also fits into neumann suspension box.the 8 degree is neumann standard mounting.for prestos and non neumann lathe i suggest the 18mm mounting. more flexible and also better for diamond, polycarbonate cuts.
caruso nr.125 is shipped to usa.
caruso nr.121 is shipped to france.
finally. first caruso Nr.124 is shipped to usa. others follow now…
caruso cutterhead delays. we still finetune and tweak the cutterhead and its electronics. so we are at least one month behind schedule.
but caruso preamp and the whole system runs stable now and we can concentrate on finetune the caruso head. thanks for your patience.
PROTECTION12. prototype of new cutterhead protection unit built. need to do some software and tests. watch out for more details.
caruso preamp boards v1.1 are in stock. they are yellow
After a lot of positive feedback on the diamonds (thanks everybody!), we are happy to annouce that a next batch is currently in production!