I have recently been pondering this same question of which Pass amp to use since I have begun experimenting with a pair of Lowther PM6a with 15-ohm silver voice coils. I've been listening to a 25W X-amp that I built, which is essentially a scaled down UGS-UP, and find the result very pleasing despite always assuming I would prefer the "single ended sound" of an XA-25, J2, F3, etc.
So, my question would be: For the Lowthers I have (currently in MLTL, but may try open baffle or Planet10's Onken) is it possible to describe the relative pluses and minuses of the XA-25, XA30.8, J2, F1, F2, F3, SIT-1, and SIT-2? I know that is a lot of amps, but I am hoping someone familiar with that Lowther and those amps (NP??) can comment.
So, my question would be: For the Lowthers I have (currently in MLTL, but may try open baffle or Planet10's Onken) is it possible to describe the relative pluses and minuses of the XA-25, XA30.8, J2, F1, F2, F3, SIT-1, and SIT-2? I know that is a lot of amps, but I am hoping someone familiar with that Lowther and those amps (NP??) can comment.
remark - passive TVC demands big Cojones from Source, to be driven properly ( low Rout)
BA-3 can be set in various ways , regarding THD spectra
same applies to F5 having 3rd trimpot
so, let your gut guide you which one ..... if you going to make it in proper way, you need to learn how to set THD SPectra ......... read ARTA and REW related threads
BA-3 can be set in various ways , regarding THD spectra
same applies to F5 having 3rd trimpot
so, let your gut guide you which one ..... if you going to make it in proper way, you need to learn how to set THD SPectra ......... read ARTA and REW related threads
I want to build properly. Thanks for the tip about REW. I'll go that route.
I'm thinking about my next build. I am nearly finished building a dual mono F5 with Django TVC.
In the same way that I like the idea of a passive pre allowing the amp to control the sound,
I like the idea of the F4 because it will allow the pre-amp to control the sound.
Assuming what I've read about the BA-3 and the F5 is true, that they are very similar, and if the BA-3 and the F5 have their P3 adjustment set in the same way, will I end up with two different sounding set-ups, or will they end up sounding the same (or similar)?
I'm thinking about my next build. I am nearly finished building a dual mono F5 with Django TVC.
In the same way that I like the idea of a passive pre allowing the amp to control the sound,
I like the idea of the F4 because it will allow the pre-amp to control the sound.
Assuming what I've read about the BA-3 and the F5 is true, that they are very similar, and if the BA-3 and the F5 have their P3 adjustment set in the same way, will I end up with two different sounding set-ups, or will they end up sounding the same (or similar)?
no two amps are the same, but be sure that they're of same Breed
fact that you can set them in various ways is just better and more convenient
razor detailed or more lush (with more foot tapping), your choice
F4 OS in its basic form is more potent and versatile than F5 in basic form, reason - more output mosfets, covering tougher loads with ease
with lower signal (power) and easier loads, THD of F4 is simply ridiculous, leaving you to play with FE to get whatever flavor you prefer
regarding that, I'm both blessed and cursed ...... my enjoyment is practically the same, whichever Papamp I'm using, on my speakers .... being extra easy load
so - both ultralow THD and ultrahigh THD ........ but I know that in case of high THD it must be heavy 2nd dominant, while for low THD I have no preference between 2nd and 3rd
yup, 3rd not being intrusive with non-complex circuits
with complex ones ...... well, I successfully stopped dealing with those eons ago
fact that you can set them in various ways is just better and more convenient
razor detailed or more lush (with more foot tapping), your choice
F4 OS in its basic form is more potent and versatile than F5 in basic form, reason - more output mosfets, covering tougher loads with ease
with lower signal (power) and easier loads, THD of F4 is simply ridiculous, leaving you to play with FE to get whatever flavor you prefer
regarding that, I'm both blessed and cursed ...... my enjoyment is practically the same, whichever Papamp I'm using, on my speakers .... being extra easy load
so - both ultralow THD and ultrahigh THD ........ but I know that in case of high THD it must be heavy 2nd dominant, while for low THD I have no preference between 2nd and 3rd
yup, 3rd not being intrusive with non-complex circuits
with complex ones ...... well, I successfully stopped dealing with those eons ago
in this case this article from German's magazine "lowbeats" (Nov. 2018) is of interest:
https://www.lowbeats.de/nelson-pass-auf-reddit-bei-ama-fragestunde/
https://www.lowbeats.de/nelson-pass-auf-reddit-bei-ama-fragestunde/
The question I have is how many different amps are doing the blessing and cursing work at ZenQuarters?... Wall of amps?
believe it or not, in this moment just 3 functional ones - Papa's Koan (F4), DEFiSIT (Papa's Koan xxx) and SissySIT
box full with finished channel pcbs removed from my T-Beds
not counting several pet amps (factory) on shelves
trying not to count few I must make, Kudos reasons; most important one Real McKay Singing Bush monoblocks
ZM Omnispoiled Omniungrateful Omnibrat
box full with finished channel pcbs removed from my T-Beds
not counting several pet amps (factory) on shelves
trying not to count few I must make, Kudos reasons; most important one Real McKay Singing Bush monoblocks
ZM Omnispoiled Omniungrateful Omnibrat
My favorite amps tend to rotate based on the recent mods. For example, my M2x was on a lower tier until I replaced its PSU with a completely new dual-mono supply. That transformed the sound of the amp, bringing it more to the level of my AJ and F6.
My F6 uses Mosfets with very high transconductance and modestly low input capacitance and gate charge figures. Its PSU is a monster based on dual-mono SLB boards. I made a slight tweak to those PSU boards after studying the sound of my re-capped Threshold CAS-2. That moved the F6 to a sonic level somewhat above my AJ. (Speaker dependent) The FQH44N10 Mosfets give the F6 sparkle and dynamics that the Aleph J doesn’t quite match.
The Aleph J is running on +/- 26.5V rails from a dual-mono CRCRC supply. I don‘t plan any more mods to this one. It is my reference amp.
My F6 uses Mosfets with very high transconductance and modestly low input capacitance and gate charge figures. Its PSU is a monster based on dual-mono SLB boards. I made a slight tweak to those PSU boards after studying the sound of my re-capped Threshold CAS-2. That moved the F6 to a sonic level somewhat above my AJ. (Speaker dependent) The FQH44N10 Mosfets give the F6 sparkle and dynamics that the Aleph J doesn’t quite match.
The Aleph J is running on +/- 26.5V rails from a dual-mono CRCRC supply. I don‘t plan any more mods to this one. It is my reference amp.
Assuming you are comparing amps on same speaker setup, sound depends on many considerations, topology e.g. SE, push-pull, EF etc., device characteristics (IC, MOSFET, BJT, SIT or tube), class A/AB or sweet spot, THD character, actual implementation and most importantly - whether it makes you happy or not.