Maggie panels have very little back EMF. The tiny blips in the MG1.7 impedance plot around 45Hz and 65Hz are the bass panel resonances. The amplifier's output impedance affects the crossover.
Ed
Ed
Like I wrote - our posts crossed - I hear the same "increased bass" in Elac BS41-BK, AN AN-K/LX and Maggie 1.7.
it's certainly just my peanut brain, but you succeeded in confusing me with various posts, so I need reset
shall I take post #40 as 0+1?
from that, I think only way to explanation is measuring THD Spectra of SE in BA3Bal to F4 bridged vs. Bal in BA3bal to F4 bridged
it looks to me that in second case you get strong suppression of even harmonics, so 3rd dominant
tried including flipping the phase of speakers in above game?
^ Post 40 is for general consumption, yes. Post 42 was a clarification for Ed.
I sent a PM to the fellow who built this BA3, see what he says.
Yes, I did expect from the very beginning that running the bridged amps would affect the 2nd vs 3rd order harmonics.
I just didn't expect that the running running it balanced from Iron to BA3 would also affect the bass so much.
No, I have not flipped the phase. Running (amp R+ to speaker +) and ( amp L+ to speaker -).
I was almost musing that if I had Maggies that could be biamped, I should run the BA3-F4 bridged to the bass panel and the XA252 to the tweeters....
Now I need new speakers....
.... or drink more IPA.
I sent a PM to the fellow who built this BA3, see what he says.
Yes, I did expect from the very beginning that running the bridged amps would affect the 2nd vs 3rd order harmonics.
I just didn't expect that the running running it balanced from Iron to BA3 would also affect the bass so much.
No, I have not flipped the phase. Running (amp R+ to speaker +) and ( amp L+ to speaker -).
I was almost musing that if I had Maggies that could be biamped, I should run the BA3-F4 bridged to the bass panel and the XA252 to the tweeters....
Now I need new speakers....
.... or drink more IPA.
culprit is not in Iron Pre, magnetic coupling between phases in autoformer is bespoke
culprit is not in F4, it's bridged in both cases
culprit is in BA3FE stage, difference in output THD Spectra depending how it's driven - SE or Bal
culprit is not in F4, it's bridged in both cases
culprit is in BA3FE stage, difference in output THD Spectra depending how it's driven - SE or Bal
^ I believe that is the case. I reached out to the builder about it.
But to be honest, I (we) like the way it sounds. So, unless you come up with a proper Biggvs Dickvs 454 SIT with 100 wpc, I think the Maggies have found their amp ( unless somehow an F5Tv3 were to appear... ). And I could always drive the A2 balanced directly from the Iron Pre as well.
And I got a YITWDAF4 kit so I can use that for the other F4 if I need to do drive the other F4 with an Iron Pre..... in any event I'm sitting on a couple of tubed preamps that drive 20Vrms.... so no problemo.
I think this year the priority will be to finish early on the P3 op amp rolling, I hear differences. I've done the all but one Burson and I can say that the V7s are a proper upgrade over the previous generations. My last comparo will be the V7 Classic vs Classic.
Then I'll move on to the rest.
After that, I think I need to work on the LP12 Keel and Ekos tonearm. Even with my guy giving good deals and hopefully finding me a used Ekos SE, it will not be cheap. I gotta due it quick enough so I'm still working to pay for that one.
Heck, I might have to sell some stuff. Wanna buy an SL1000HF and MDP700? With editing board.
But to be honest, I (we) like the way it sounds. So, unless you come up with a proper Biggvs Dickvs 454 SIT with 100 wpc, I think the Maggies have found their amp ( unless somehow an F5Tv3 were to appear... ). And I could always drive the A2 balanced directly from the Iron Pre as well.
And I got a YITWDAF4 kit so I can use that for the other F4 if I need to do drive the other F4 with an Iron Pre..... in any event I'm sitting on a couple of tubed preamps that drive 20Vrms.... so no problemo.
I think this year the priority will be to finish early on the P3 op amp rolling, I hear differences. I've done the all but one Burson and I can say that the V7s are a proper upgrade over the previous generations. My last comparo will be the V7 Classic vs Classic.
Then I'll move on to the rest.
After that, I think I need to work on the LP12 Keel and Ekos tonearm. Even with my guy giving good deals and hopefully finding me a used Ekos SE, it will not be cheap. I gotta due it quick enough so I'm still working to pay for that one.
Heck, I might have to sell some stuff. Wanna buy an SL1000HF and MDP700? With editing board.
BTW, something that somehow got missed.
I ran the XA252MOS into its protection, on the right channel. This time it worked, I heard a channel imbalance and when I turned down the left side (which was working fine) I could hear some weird sounds from the right channel. When I turned down the volume every thing came back up, so I kept the volume in the Iron Pre to below 2 o'clock. I have the BA3 set to its low gain setting.
What's with the right channel anyhow?
I ran the XA252MOS into its protection, on the right channel. This time it worked, I heard a channel imbalance and when I turned down the left side (which was working fine) I could hear some weird sounds from the right channel. When I turned down the volume every thing came back up, so I kept the volume in the Iron Pre to below 2 o'clock. I have the BA3 set to its low gain setting.
What's with the right channel anyhow?
Yeah... ghost alright.... it's been years since I've run anything into a protection mode... I blew a tweeter in my ADS L810s back in '84 when I was playing Michael Jackson's Beat It... but that because I had a 40 wpc KA3500 integrated, it was turned to 11 and clipped. Before that I blew a midrange in one of the L810 speakers when I was playing Eric Clapton and Freddie King Farther On Up The Road... with the Sansui G7500 turned up to 11.
I mean, I've blown speakers, but never an amp... never a woofer... before... hmm...
Funny how you remember those events after all of those years.
I mean, I've blown speakers, but never an amp... never a woofer... before... hmm...
Funny how you remember those events after all of those years.
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Coincidentally, or not, I have had right channel hickups in my SET version when visitors with "impaired hearing" come by for a listen 😊
ZM suggested "solder 220R in parallel to diode part of optocoupler". I have done this but have not put it to the test. And don't know if this applies to your version.
ZM suggested "solder 220R in parallel to diode part of optocoupler". I have done this but have not put it to the test. And don't know if this applies to your version.
OK..... then.... what kind of hiccups are these? Do I have to pay attention?
You mean, I can't get half drunk on vodka tonics and crank up Spinal Tap with aBaNdOn? 🍸🍸🍸🍸
You mean, I can't get half drunk on vodka tonics and crank up Spinal Tap with aBaNdOn? 🍸🍸🍸🍸
Q1 has given up the spirit a few times on high volumes and I now consider this an inherent "speed limiter". Maybe the resistor tweak above will help!
Since I’m actively assembling the XA252 MOS version, this modification seems pretty important. 
Is the parallel resistor used across both opto's?
Sorenm, do you remember the post# that ZM shared this info?
Is the parallel resistor used across both opto's?
Sorenm, do you remember the post# that ZM shared this info?
I'm keeping mine with NO changes. Just use more efficient speakers I guess... and not play Euro Techno, I guess.
Do they have Serbo-Croatian Punk Rock?
Do they have Serbo-Croatian Punk Rock?
OK, I just got my reply. And it makes a lot of sense.
As wired, my BA3 requires balanced inputs to swing 40V into the bridged F4. That makes sense. So what I'm hearing is the F4s being run at full tilt when I wire the Iron Pre Bal to the BA3.
It does have some serious COJONES. It's working correctly then. The sucker can probably drive some bigger Maggies.
Folks, so we got two DIY amps now for Maggies.... A2 and BA3/F4s bridged. Maybe if I feel rich I might get a pair of XA100.8 amps... Maybe Mister Pass might feel rich and send me a pair for a long term "review"? 🙂 🤓😉
Another question then... what is the maximum power of the XA253 MOS? It goes to almost 50wpc into class A.... does it go into AB after that? I thought the FW XA25 goes above 100 wpc in the reviews I've seen.
Hmm... the XA100.8 weights 107 lbs EACH.... and no handles? Used, in Hifishark they go for $12K... I guess if you got that kind of money, you can afford the chauffeur and head gardener to come into the mansion and move them into your private audio salon.... Gulp..... Maybe Nelson Pass needs to explore Class NPcore-D for us older guys who really don't wanna like slip a disk...
As wired, my BA3 requires balanced inputs to swing 40V into the bridged F4. That makes sense. So what I'm hearing is the F4s being run at full tilt when I wire the Iron Pre Bal to the BA3.
It does have some serious COJONES. It's working correctly then. The sucker can probably drive some bigger Maggies.
Folks, so we got two DIY amps now for Maggies.... A2 and BA3/F4s bridged. Maybe if I feel rich I might get a pair of XA100.8 amps... Maybe Mister Pass might feel rich and send me a pair for a long term "review"? 🙂 🤓😉
Another question then... what is the maximum power of the XA253 MOS? It goes to almost 50wpc into class A.... does it go into AB after that? I thought the FW XA25 goes above 100 wpc in the reviews I've seen.
Hmm... the XA100.8 weights 107 lbs EACH.... and no handles? Used, in Hifishark they go for $12K... I guess if you got that kind of money, you can afford the chauffeur and head gardener to come into the mansion and move them into your private audio salon.... Gulp..... Maybe Nelson Pass needs to explore Class NPcore-D for us older guys who really don't wanna like slip a disk...
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what could be nice is to be sure that - when you speak of sound character- you're comparing things at so-so-same SPL
Thanks Sorenm!
I understand now why my searching came up empty about this mod.
I’ll move over to the main thread for further discussion so not to clutter up here.
I understand now why my searching came up empty about this mod.
I’ll move over to the main thread for further discussion so not to clutter up here.