Please take a look at the above FR it is the 1watt 1 meter measurement. You'll see why I said 88db. If I look at 19khz sensitivity is 90db.....overall the fr sensitivity would be rated at about 110db..... But the goal is a flat as possible response. So depending on how I sculpt the signal will affect the end result.
This is the comment a person said after another suggested the modulus and stated this amp makes class a pointless endeavor...What do you think about this comment?
At the bottom are pairs of 18"s (18h+).... It seems most people use class D for subs nowadays.
The paired 18"s will be ran in 16ohms unless I can be find reason why 4ohms provide better SQ. In 16ohms it seems 100watts gets me to 115db at 30hz, which is the goal spl.
The 15" mid is 16ohms, seems 40watts gets me to max spl.
I think I see where you are headed. Of course disregard the sub(s) if amplified separately. Without baffle step compensation nor padding the AE TD15M sensitivity below 300 Hz is around 95-96 according to published graph. Then you could EQ the compression driver to get it flat to 14 kHz then gentle roll off. In this case 10 watts should be ok for normal listening level, and 100 watt would be able to rock the house. If to extend the top end above 14 kHz you pad the midrange by say 6 dB more (to 89 dB sensitivity), then quadruple the power required. Someone correct me if I am wrong! I agree with others that this seems like a waste of sensitivity besides limiting the kind of amps you can experiment with - unless you like listening at low levels - but this is besides the point isn't it? This is DIY of course 🙂. Nelson Pass published a low distortion 100 watt class AB design (AB100 it is called I think) that might suit you. whatever you decide, please share!
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Yes each driver will be powered per channel (bass, mid, treble)
That all goes to say that yes there are some pros to not attenuating the signal so much (lack of raising noise floor from the unity gain) but the mechanical efficiency remains unchanged, thus the excursion characteristics remain unchanged per spl, thus the THD characteristics of the driver remain unchanged
I have nuetrally voiced the Compression driver using my crown cts2000 (one subtractive filter (-10 shelf) got me to about +/-2.5db) and had no issues with noise floor or achieving volume....It was quieter than the class D amps in my kris at least lol...So with an even better amp, all should be well.
This is untrue....sensitivity is a matter of mechanical first and foremost....if I boost the signal on my active crossover on a 88db sensitivity driver I don't all of a sudden have the performance of a 114db driver lol....It don't work that way. If I attenuate the signal of a 114 db driver to 88db the only issue is noise floor of the dsp and amp....the driver is still receiving the same amount of power (literally) to achieve the same spl no matter what because mechanical sensitivity remains unchanged....So in my case you can lookout the natural 1 watt FR, anywhere I cut, receives less power....If I level the response at 19khz the sensitivity is 90db but where I cut will receive much less than 1 watt when supplied the same levels from the amp. Which is why I said the statement was untrue about input signal attenuation being a waste
That all goes to say that yes there are some pros to not attenuating the signal so much (lack of raising noise floor from the unity gain) but the mechanical efficiency remains unchanged, thus the excursion characteristics remain unchanged per spl, thus the THD characteristics of the driver remain unchanged
I have nuetrally voiced the Compression driver using my crown cts2000 (one subtractive filter (-10 shelf) got me to about +/-2.5db) and had no issues with noise floor or achieving volume....It was quieter than the class D amps in my kris at least lol...So with an even better amp, all should be well.
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- this statement leaves me concerned regarding the modulus amps....otherwise, the super low noise floor and the decent pricing of these amps, plus they are already assemble (right?) makes them a no brainer.
I missed that... (thought you were going passive). Never mind my comment then. I am big fan of high efficiency drivers myself, even if used at low volume, for the sake of less distortion.
Hi...
ZM do we need any kind of matching at all on parts?
Case is that i might start collecting parts for a future build 🙂
Nice work as allways ZM 🙂
Rgds; Jesper
ZM do we need any kind of matching at all on parts?
Case is that i might start collecting parts for a future build 🙂
Nice work as allways ZM 🙂
Rgds; Jesper
Okay then 🙂
Them jfets are dual like 2sk389 (was)! I think 🙂
I see that the drain current is proberly around 8ma, guessing that the two in a package are closed matched.
Also i see that they are paralleled 3 + 3 into the circuit. So i defently need help howto match them proberly to fit the circuit.
I can handle smd parts, but cannot figure out how they must be matched here 😱
Jesper...
Them jfets are dual like 2sk389 (was)! I think 🙂
I see that the drain current is proberly around 8ma, guessing that the two in a package are closed matched.
Also i see that they are paralleled 3 + 3 into the circuit. So i defently need help howto match them proberly to fit the circuit.
I can handle smd parts, but cannot figure out how they must be matched here 😱
Jesper...
if you take a look at pictures in post #2 , you'll see that I made it with 2SK2145BL (only), 3up,3down
buffer Iq is 20mA
on my pcbs, I didn't made provision of any other JFet footprint, as I did in some other amps, where is provision for both tiny SMD buggers and for any decent TO92 critters
of course, if one is making own pcb, any decent JFet can be used for buffer - if same sex JFets, then 2SK170 is OK, or any with similar xconductance ....... of course - more of them in parallel getting lower Rout of buffer, which can be only better to driving autoformer
2SK2145 is in fact dual JFet in one smal case, but I'm treating them simply as one JFet .... so - you can even say that there are 6up,6down
matching is necessary of course; tight triplet up, tight triplet down ....... and then - for nicest possible behaving regarding DC offset in temperature domain, it is advisable that these two trilpets are close
in best case scenario, one buffer is made of tight sextet of JFets, but in praxis - that is not necessary
buffer Iq is 20mA
on my pcbs, I didn't made provision of any other JFet footprint, as I did in some other amps, where is provision for both tiny SMD buggers and for any decent TO92 critters
of course, if one is making own pcb, any decent JFet can be used for buffer - if same sex JFets, then 2SK170 is OK, or any with similar xconductance ....... of course - more of them in parallel getting lower Rout of buffer, which can be only better to driving autoformer
2SK2145 is in fact dual JFet in one smal case, but I'm treating them simply as one JFet .... so - you can even say that there are 6up,6down
matching is necessary of course; tight triplet up, tight triplet down ....... and then - for nicest possible behaving regarding DC offset in temperature domain, it is advisable that these two trilpets are close
in best case scenario, one buffer is made of tight sextet of JFets, but in praxis - that is not necessary
ZM,
When you have time...
Please make a general building tips and tricks thread for the Babelfish M25 R.2 & SET versions. You can probably copy and paste a lot from the original M25 tips and tricks but add more specifics too.
Thank you,
Anand.
When you have time...
Please make a general building tips and tricks thread for the Babelfish M25 R.2 & SET versions. You can probably copy and paste a lot from the original M25 tips and tricks but add more specifics too.
Thank you,
Anand.
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I will , hopefully tonight
as I just wrote in Old Soul thread - there are just two specific areas ( besides lazy and slow pcb assembly - longer it takes, longer it brings you pleasure) needing some logical approach - setting Iq and offset of input buffer, and same for OS
as I just wrote in Old Soul thread - there are just two specific areas ( besides lazy and slow pcb assembly - longer it takes, longer it brings you pleasure) needing some logical approach - setting Iq and offset of input buffer, and same for OS
ZM,
Just got off the phone and ordered a bunch of CINEMAG CMOQ-4HPC's! Hopefully they will arrive in 1-2 months, they are running a backlog right now because of so many orders. For reference, it's best to call Cinemag directly since they are overloaded with emails at the moment.
Best,
Anand.
Just got off the phone and ordered a bunch of CINEMAG CMOQ-4HPC's! Hopefully they will arrive in 1-2 months, they are running a backlog right now because of so many orders. For reference, it's best to call Cinemag directly since they are overloaded with emails at the moment.
Best,
Anand.
Thank you ZM.
I have received kit package today.
I emailed Cinemag directly last month but no answer
so I ordered CinemagCMOQ-4HPC from Don-Audio web site.
They send me invoice then paid via PayPal 3weeks ago.
I sent them email but no answer until now.
I wonder if it's common that wait long time?
I have received kit package today.
I emailed Cinemag directly last month but no answer
so I ordered CinemagCMOQ-4HPC from Don-Audio web site.
They send me invoice then paid via PayPal 3weeks ago.
I sent them email but no answer until now.
I wonder if it's common that wait long time?
It seems that correspondence these days is harder, with everyone
Just e-mail them again
besides that I can't say anything more - I didn't had dealings with Don Audio, but I know few people which had, and everything did go fast and efficient
Just e-mail them again
besides that I can't say anything more - I didn't had dealings with Don Audio, but I know few people which had, and everything did go fast and efficient
Tamra,
I called Cinemag a few weeks ago and placed my order directly. The problem is that they are running low on staff and do not have enough resources to answer email etc... The gentleman told me that the manufacturing delays of these transformers are due to the high volume of orders; he expects some shipments to go out in September. Since Don-Audio is a regional distributor, they will have to wait just like the rest of us.
That being said, for these types of circuits I believe the wait is justified since the Cinemag particularly the high nickel version, is the most transparent when compared to competitors from Edcor and Jensen.
ZM,
When you have time...
Please make a general building tips and tricks thread for the Babelfish M25 R.2 & SET versions. You can probably copy and paste a lot from the original M25 tips and tricks thread but add more specifics too.
Thank you,
Anand.
Thank you.
I have got a response from Don audio that
auto former have shipped.
I was a little too excited to wait...
I have got a response from Don audio that
auto former have shipped.
I was a little too excited to wait...
first post edited, now containing almost everything needed for successful and stress-free setting procedure
I believe that there is no need for separate Tips'n'Tricks thread
I completed my M25 build using Cinemag CMOQ-4 transformers a couple of days ago. And although the amplifier probably insn't fully burned in yet, it already sounds really good. I have not had a chance to compare it to my regular M2 using Toshiba SK1530/SJ201, but I can tell that the M25 probably sounds cleaner and certainly more powerful.
I want to thank Zen Mod for a great design 🙂
I want to thank Zen Mod for a great design 🙂
with easy speakers, it'll probably sound little cleaner than your M2
with harder speakers, it'll sound much cleaner
with harder speakers, it'll sound much cleaner