Why do you need balanced? It can be good to have both, I guess. The measurement freaks at ASR requires it to listen to music.
Yeah, the V-FET is very sweet, but can get a type of sound like one of those toys with sand in a wooden tube that is supposed to sound like the ocean. Difficult to explain. I am using it together with Nutube B1 triode preamp which is another 2nd harmonics distortion generator, against recommendation.
I don't use it for midbass, 10W is apparently not enough juice for the power peaks that can occur in bass. Looking forward to listen to the J2 if I can source the rest of the parts and PCB.
Yeah, the V-FET is very sweet, but can get a type of sound like one of those toys with sand in a wooden tube that is supposed to sound like the ocean. Difficult to explain. I am using it together with Nutube B1 triode preamp which is another 2nd harmonics distortion generator, against recommendation.
I don't use it for midbass, 10W is apparently not enough juice for the power peaks that can occur in bass. Looking forward to listen to the J2 if I can source the rest of the parts and PCB.
Very inspiring!
Makes me want to pause the music and plug in the soldering iron.
Thanks. To be honest, I'm retired and living in east central Wisconsin. I have plenty of time during the winter months, and there are several. I spent 46 years in the Auto business, traveling 4 - 5 days a week, so I'm making up for all the time I was not at home to do this kind of work.
I just bought BAL LXMINI-SUB R2 and soldered all parts It works well all testing point but if I need to use with other drivers SUB, WOOF, MID, TW how can I calculate R, C value ?
Go to FIRSTWATT.com, find the articles tab, then open the 6-24 article. Nelson supplied a link to a site that has the filter calculators, make sure you select the 12dB filter on the calculator.
Hello Marcus Solomon,
Nelson Pass offered a link to the download of the microsim-software (testversion) and the circuit in microsim to play around with those values
in the LX-mini-crossover.
https://www.firstwatt.com/pdf/art_lxmini crossover.pdf
check last page - last two paragraphs.
The circuit of the LX-mini-active crossover has an equalization built in. It is different to the 6-24-AXO.
Or you could simulate the circuit in LTspice?
Cheers
Dirk
Nelson Pass offered a link to the download of the microsim-software (testversion) and the circuit in microsim to play around with those values
in the LX-mini-crossover.
https://www.firstwatt.com/pdf/art_lxmini crossover.pdf
check last page - last two paragraphs.
The circuit of the LX-mini-active crossover has an equalization built in. It is different to the 6-24-AXO.
Or you could simulate the circuit in LTspice?
Cheers
Dirk
Thank you, now I desoldered all R,C from original value (BOM) and prepare to measure their crossover point soon.
I have the SLOB speakers with CUBE FC8 drivers for the full range, Nelson Pass was kind enough to send me the schematic for the ACN/LX mini using the CUBE full range drivers that he built. I was trying to understand the entire schematic with the buffers, and I'm not sure which version is correct for his schematic. I used the R, C & Q designations that match the LX mini ACN printed circuit board from the DIY Store.
I need help to understand which schematic version, A or B, is correct.
I need help to understand which schematic version, A or B, is correct.
Attachments
10K to ground on the Source resistors of the Jfets should be more like 100,
depending on the Vp of the Jfet. The 100 meg resistor is simply open, no
resistor. After that just follow the values you see on the sim.
depending on the Vp of the Jfet. The 100 meg resistor is simply open, no
resistor. After that just follow the values you see on the sim.
I finished the schematic, on the bottom of the page is the slip of paper that is included with the JFET's and resistors when the lx-mini ACN PCB is purchased from the DIY store. IGNORE the 10K resistors, they are not used in this version, the 125 ohm resistors are for the JFET's source resistors.
The two completed CUBE ACN boards used 150 ohm source resistors, the 125 ohm source resistors were used in the single ended version I built.
The two completed CUBE ACN boards used 150 ohm source resistors, the 125 ohm source resistors were used in the single ended version I built.
Attachments
I have the single ended version in my main system with a Sony VFET P Channel amp for the CUBE FC-8 drivers and a Singing Bush THF-51s amp for the woofers (SLOB).
I finished a Balanced version yesterday, rainy day, to use with:
Both of the ACN's use 2SK170 BL devices for the buffers (J113 for CCS), I bought 50 for $2 each and ended up with 6 matched quads and 7 matched pairs.
This should keep me busy swapping amps in and out for the next couple of years.
I finished a Balanced version yesterday, rainy day, to use with:
- ACA V1.6 mono blocks
- J2 clone
- ALEPH J w/Semisouth output devices
Both of the ACN's use 2SK170 BL devices for the buffers (J113 for CCS), I bought 50 for $2 each and ended up with 6 matched quads and 7 matched pairs.
This should keep me busy swapping amps in and out for the next couple of years.
Attachments
as used in most usual active crossover network both discrete versions and with Op-AMP's also here is to find the topology according Sallen-Key (R.P. Sallen and E.L. Key: A Practical Method of Designing RC Active Filters, IRE Transactions on Circuit Theory, Issue1, pg. 74-85, from 1955).
Due the poor handling (especially very complicated adjusting/variation of the wanted f3) the MFB topology (multiple feedback) is very unpopular with developers. But some guys claim, in order of best sound character particularly in the upper frequency area the MFB topology is definitely preferable in opposite to the most used Sallen Key topology.
Is this true only in case if low cost op amps are in use or in general ?
Thanks for some comments in advance.
Maybe to this question exist an associate thread here on diyaudio.
Some URLs:
https://ez.analog.com/amplifiers/f/q-a/15186/filter-wizard-noise-in-sallen-key-vs-multiple-feedback
https://electronics.stackexchange.c...-key-filter-over-a-normal-second-order-filter
https://www.ele.uri.edu/~diceccoj/Final_w_Pic.pdf
Due the poor handling (especially very complicated adjusting/variation of the wanted f3) the MFB topology (multiple feedback) is very unpopular with developers. But some guys claim, in order of best sound character particularly in the upper frequency area the MFB topology is definitely preferable in opposite to the most used Sallen Key topology.
Is this true only in case if low cost op amps are in use or in general ?
Thanks for some comments in advance.
Maybe to this question exist an associate thread here on diyaudio.
Some URLs:
https://ez.analog.com/amplifiers/f/q-a/15186/filter-wizard-noise-in-sallen-key-vs-multiple-feedback
https://electronics.stackexchange.c...-key-filter-over-a-normal-second-order-filter
https://www.ele.uri.edu/~diceccoj/Final_w_Pic.pdf
@elwood625
A lot of parallels here between with what I am thinking and doing and with what you have been doing. I also bought some 2SK170s and will use them in my builds with J113s CCSs. What criterion are you using for 2SK170 matching? Vp and Idss window size for matching.
Also envious of the CUBE drivers but it easier to have a number of amps and swap them then it is with speakers. Life's a bummer.
I matched for Idss, since the J113's CCS are around 8mA, I used matched pairs above 8mA and used them so that they are in the same position, one for left channel and one for right channel.
With the balanced version, I used matched quads in the same position with one for L-, L+, R-, R+.