There is an article slowly in process called BOB, the Big
Open Baffle project. It is big on two levels - it starts
with very large baffles and slowly goes to smaller ones,
and it has large number of drivers, mostly full range with
woofer assist.
Unfortunately it has turned into War and Peace in
terms of its length. I am planning to break it up into a
series.
😎
Thanks Nelson.
Just one more thing it would be nice if you could include in your article the difference between Eminence Alpha vs Deltalite II 2515.
I know the deltalite II has low QTS of 0.38 but it looks like you should be able to get at least 90dB/2.83V on a 50cm baffle (if you run them in pairs) and if you put them on a wide baffle eg 1m then a single driver will put out 96dB/2.83V (according to Troels).
I got this gut feeling I will prefer sonics of the deltalite over the Alpha.
I would be prepared to have them shipped to you for testing if you are interested
Just one more thing it would be nice if you could include in your article the difference between Eminence Alpha vs Deltalite II 2515.
I know the deltalite II has low QTS of 0.38 but it looks like you should be able to get at least 90dB/2.83V on a 50cm baffle (if you run them in pairs) and if you put them on a wide baffle eg 1m then a single driver will put out 96dB/2.83V (according to Troels).
I got this gut feeling I will prefer sonics of the deltalite over the Alpha.
I would be prepared to have them shipped to you for testing if you are interested
I knew I chose the wrong career path. I should have become a vicar.
Vicars don't get married either do they 😉😀
Not only you could became a Vicar at any time but can also pick a job that will let you get married.
Snag is the one I did know (my Theology tutor at the Zuccante polytechnic in Venice)
Use to get quite a few propriety left as inheritance by the odd Old widow when she died.
If you are not in to marriage You could became a Franciscan monk I use to know one the used to make telescope lenses by polishing the glass by hand and sell those all over the world.
Back to speakers
I mentioned the old drivers with the winding instead of the magnet
Does any one remember them?
I believe that a couple of years ago this was done by a reputable manufacturer with very good results but can’t remember who did.
I think that maybe 90 dB can be surpassed with this method.
Any Idea?
Snag is the one I did know (my Theology tutor at the Zuccante polytechnic in Venice)
Use to get quite a few propriety left as inheritance by the odd Old widow when she died.
If you are not in to marriage You could became a Franciscan monk I use to know one the used to make telescope lenses by polishing the glass by hand and sell those all over the world.
Back to speakers
I mentioned the old drivers with the winding instead of the magnet
Does any one remember them?
I believe that a couple of years ago this was done by a reputable manufacturer with very good results but can’t remember who did.
I think that maybe 90 dB can be surpassed with this method.
Any Idea?
F5 sound with Fairchild vs Toshiba MOSFETS
My first pair of F5 channels used unmatched Fairchild FQA19N20C and FQA12P20 MOSFETS, unmatched JFETS, and 5% resistors. Oscilloscope measurements of AC voltages across the source resistors R11 and R12 showed large differences (30% +/-), indicating that the channel would leave class A operation well before reaching 25 watts output.
The first pair of F5 channels sounded great, but not satisfied with the measurements I decided to build another pair of channels using matched Toshiba 2SK1530 and 2SJ201 MOSFETS, matched FJETS, and 1% resistors. Oscilloscope observations indicate almost identical AC signals on R11 and R12.
To my ears (not the greatest at age 67) I prefer the sound of the first pair of channels. Is likely due to liklyhood that the 1st pair has much higher 2nd harmonic distortion and the "tube sound"? I have no distortion analyze to measure the differences.
My first pair of F5 channels used unmatched Fairchild FQA19N20C and FQA12P20 MOSFETS, unmatched JFETS, and 5% resistors. Oscilloscope measurements of AC voltages across the source resistors R11 and R12 showed large differences (30% +/-), indicating that the channel would leave class A operation well before reaching 25 watts output.
The first pair of F5 channels sounded great, but not satisfied with the measurements I decided to build another pair of channels using matched Toshiba 2SK1530 and 2SJ201 MOSFETS, matched FJETS, and 1% resistors. Oscilloscope observations indicate almost identical AC signals on R11 and R12.
To my ears (not the greatest at age 67) I prefer the sound of the first pair of channels. Is likely due to liklyhood that the 1st pair has much higher 2nd harmonic distortion and the "tube sound"? I have no distortion analyze to measure the differences.
Back on topic
Got my F5 to see Day light for the first time yesterday
And today a bit of listening...
Not the Ideal set up thin Living Room and an Akay SS1 as preamplifier and 5 meters long cables.
Source is an Elite with balanced IN solid-state passive RIAA Phono stage
Speakers are 4 Homs Polk LSi 15 (Bad support from those dudes so) just waiting to be replaced by a much much beter set of Sonus Faber Cremonas.
At the moment is just a twin Toshibas at 26 V 3.5A rails.
After a few sides just to warm up I started up as usual with Grace Jones Slave to the Rhythm Is a direct Metal Mastering copy MANHATAN Island Record distributed By EMI LC7365.
Grace Jones????
Well I don't think I have ever played a single track from in its entirety BUT recording is absolutely one of the best really fast attack and good Dynamics and the bit of silence are just perfect.
If you can get a system to play Grace Jones Laughing is worth listening a bit more.
(Well it actually works for me.
The Little Sugden did pass the Grace Jones test but did not make it later (not enough watts)
A 250 W Krill did not. Sounded too artificial.
So F5 made it? Well yes but couple of issues to sort out (my short coming mostly)
So tick for now.
Next on the spinner
Led Zeppelin HAT (S) 421-40 a Spanish version in pink of Zep 1
Babe I'm gonna Leave you
Gorgeous guitar can really pick up the nails scratching the strings and each single note.
Doors L.A. Woman Elektra EKS-75011
Riders of the storm
Details and staging really good the bit of rain a bit to artificial a poorer recording of the sound effects that what I would I have liked.
IMO Natural sounds Laughing Rain Hand Clapping can give you a good idea of how a system sounds.
So I am looking fore same more rain sound so
Pure Cult Box set had a track with same
BEGA 130 B 4 Album Box set
I put Brother Wolf and sister Moon under the needle and Crap
This was recorded Live at the Marquee in London normally sound is pretty good there
in this case it was off the spinner in a jiffy the vocals just to painful to listen 2.
This is a fast amplifier with plenty of details but not tolerant of poor recordings.
THE Zep track brilliant
Live stuff???????
I will have to go back to the Cult another time (same fond memories lost?)
Same more Live stuff
And Girl friend joins in
Only one record must go Uriah Heep Sun Rise the first record She Brought when it came out
This is the 1973 Live Album Bronze Records ISLD1
Again not that good fuzzy at least.
So back in the sleeve and time for another of her favourites.
The Temptation Master piece
While she is there listening I got a chance to pump up the volume
The SS1 knob is jammed solid at the end and my meter measured 5.36 Volts peak during this section.
I was going to play a bit of it but at about 7 minutes in on listening to masterpiece I turn around and somtink wrong with her.
"What Up?"
Nothing
What Up? sound bad?
Not sound realy good
Just remembering when I was playing this in the shop in Rwanda and remembering the Old Times....
Tanks Papa for this few magic moments.
But back on topic the al of masterpiece got played and is difficult to explain but same magic is taking place.
No listening Fatigue stage is tri dimensional and seems to extend way out in all planes dimensions I got carried away listening to the whole album while I should have taken same notes I just remember one bit when the band is hand clapping away and can tell you exactly where they are positioned and how tall they are.
(Is it just getting up to the right temperature?)
Maybe not to the point to say whose got sweaty hands but near enough (I pretty sure I will get there soon. Just a few tweaks)
I few more tracks got trough and finally one of my favourite records.
The Chieftains Bonaparte's Retreat Shanachie Records 79026
This is a very old copy worn and full of ticks and toks but absolutely fantastic
Tin whistle painful at time just as it should be and 2 of those playing one a bit to the left and 1 yard in front of the other not kidding you
The dept and detail of the bodhran (Irish Drum ranging from 26 to over 50 in) is unbelievable if it wasn’t for the poor state of the record it would have been there in my living room.
I could go on for quite a bit just about the sound of the bodhran just do yourself a favour go and listen to one live then you will understand.
While you there Murphy compared to Guinness this is how the F5 sounds like
You may forget the pointer to the Grace Jones record you definitely should get this Album IMO just the Kind of music the F5 is designed for.
What was meant to be a couple of tracks became the whole Album and if I could have had a bit more volume out of the SS1 I would have played the lot again.
The F5 how good is it? Goose pimples and hair rising good already and I have only just started.
Maybe out of topic
R3 and R4 need to come down in value quite a bit (especially with the Toshibas)
And I need to twiddle the pots for beter sound instead of 0 DC offset
but the plan is for same more stuff to be played tomorrow same heavy stuff and see how it copes (provided that neighbours got out for the day)
I may even change the gain of the MC stage to take knob of the SS1 back a bit.
Over and Out.
For now.
Got my F5 to see Day light for the first time yesterday
And today a bit of listening...
Not the Ideal set up thin Living Room and an Akay SS1 as preamplifier and 5 meters long cables.
Source is an Elite with balanced IN solid-state passive RIAA Phono stage
Speakers are 4 Homs Polk LSi 15 (Bad support from those dudes so) just waiting to be replaced by a much much beter set of Sonus Faber Cremonas.
At the moment is just a twin Toshibas at 26 V 3.5A rails.
After a few sides just to warm up I started up as usual with Grace Jones Slave to the Rhythm Is a direct Metal Mastering copy MANHATAN Island Record distributed By EMI LC7365.
Grace Jones????
Well I don't think I have ever played a single track from in its entirety BUT recording is absolutely one of the best really fast attack and good Dynamics and the bit of silence are just perfect.
If you can get a system to play Grace Jones Laughing is worth listening a bit more.
(Well it actually works for me.
The Little Sugden did pass the Grace Jones test but did not make it later (not enough watts)
A 250 W Krill did not. Sounded too artificial.
So F5 made it? Well yes but couple of issues to sort out (my short coming mostly)
So tick for now.
Next on the spinner
Led Zeppelin HAT (S) 421-40 a Spanish version in pink of Zep 1
Babe I'm gonna Leave you
Gorgeous guitar can really pick up the nails scratching the strings and each single note.
Doors L.A. Woman Elektra EKS-75011
Riders of the storm
Details and staging really good the bit of rain a bit to artificial a poorer recording of the sound effects that what I would I have liked.
IMO Natural sounds Laughing Rain Hand Clapping can give you a good idea of how a system sounds.
So I am looking fore same more rain sound so
Pure Cult Box set had a track with same
BEGA 130 B 4 Album Box set
I put Brother Wolf and sister Moon under the needle and Crap
This was recorded Live at the Marquee in London normally sound is pretty good there
in this case it was off the spinner in a jiffy the vocals just to painful to listen 2.
This is a fast amplifier with plenty of details but not tolerant of poor recordings.
THE Zep track brilliant
Live stuff???????
I will have to go back to the Cult another time (same fond memories lost?)
Same more Live stuff
And Girl friend joins in
Only one record must go Uriah Heep Sun Rise the first record She Brought when it came out
This is the 1973 Live Album Bronze Records ISLD1
Again not that good fuzzy at least.
So back in the sleeve and time for another of her favourites.
The Temptation Master piece
While she is there listening I got a chance to pump up the volume
The SS1 knob is jammed solid at the end and my meter measured 5.36 Volts peak during this section.
I was going to play a bit of it but at about 7 minutes in on listening to masterpiece I turn around and somtink wrong with her.
"What Up?"
Nothing
What Up? sound bad?
Not sound realy good
Just remembering when I was playing this in the shop in Rwanda and remembering the Old Times....
Tanks Papa for this few magic moments.
But back on topic the al of masterpiece got played and is difficult to explain but same magic is taking place.
No listening Fatigue stage is tri dimensional and seems to extend way out in all planes dimensions I got carried away listening to the whole album while I should have taken same notes I just remember one bit when the band is hand clapping away and can tell you exactly where they are positioned and how tall they are.
(Is it just getting up to the right temperature?)
Maybe not to the point to say whose got sweaty hands but near enough (I pretty sure I will get there soon. Just a few tweaks)
I few more tracks got trough and finally one of my favourite records.
The Chieftains Bonaparte's Retreat Shanachie Records 79026
This is a very old copy worn and full of ticks and toks but absolutely fantastic
Tin whistle painful at time just as it should be and 2 of those playing one a bit to the left and 1 yard in front of the other not kidding you
The dept and detail of the bodhran (Irish Drum ranging from 26 to over 50 in) is unbelievable if it wasn’t for the poor state of the record it would have been there in my living room.
I could go on for quite a bit just about the sound of the bodhran just do yourself a favour go and listen to one live then you will understand.
While you there Murphy compared to Guinness this is how the F5 sounds like
You may forget the pointer to the Grace Jones record you definitely should get this Album IMO just the Kind of music the F5 is designed for.
What was meant to be a couple of tracks became the whole Album and if I could have had a bit more volume out of the SS1 I would have played the lot again.
The F5 how good is it? Goose pimples and hair rising good already and I have only just started.
Maybe out of topic
R3 and R4 need to come down in value quite a bit (especially with the Toshibas)
And I need to twiddle the pots for beter sound instead of 0 DC offset
but the plan is for same more stuff to be played tomorrow same heavy stuff and see how it copes (provided that neighbours got out for the day)
I may even change the gain of the MC stage to take knob of the SS1 back a bit.
Over and Out.
For now.
Last edited:
Can you explain a little more about that? I assume things not being symmetrical adds to distortion, then affecting the sound? Never even considered that as an option to try.
compressit
Sorry mate I would have to agree with you as my knowledge is preaty limited.
After reading the F5 paper at least 50 times only now same litle bits start to make sense
Papa or Zen would be way beter to have a go at this.
Sorry mate I would have to agree with you as my knowledge is preaty limited.
After reading the F5 paper at least 50 times only now same litle bits start to make sense
Papa or Zen would be way beter to have a go at this.
yo Sabath
Fugly! choice of music , n'est-ce pas
look here :
for plain vanilla F5 ( even Toshiba output-ed) , you need decent THD meter , to be able to let two big resistors to copulate , making smaller one
elegant Papa's trick to fool outputs that they're similar enough , all along the watchtower ...... ( ok - load line , not watchtower)
for SUSY F5 , I think that adjacent output's difference in xconductance is pretty well nulled with circ itself
so - if you wanna play with gain differentiation in any of 4 SUSY quadrant's - feel free to do that , but I expect that you'll go for another amp , long before you made more romantic F5
edit :
put In my time of dying on spinner , and you'll forget on fifi
besides that - you need some proper big cones for da muzak with those amps
😉
Fugly! choice of music , n'est-ce pas
look here :
for plain vanilla F5 ( even Toshiba output-ed) , you need decent THD meter , to be able to let two big resistors to copulate , making smaller one
elegant Papa's trick to fool outputs that they're similar enough , all along the watchtower ...... ( ok - load line , not watchtower)
for SUSY F5 , I think that adjacent output's difference in xconductance is pretty well nulled with circ itself
so - if you wanna play with gain differentiation in any of 4 SUSY quadrant's - feel free to do that , but I expect that you'll go for another amp , long before you made more romantic F5
edit :
put In my time of dying on spinner , and you'll forget on fifi
besides that - you need some proper big cones for da muzak with those amps
😉
Last edited:
So simple
Just a bit more currants to one side and then back in line with the pots.
Tanks Zen
got 4 new boards ready for etching tomorow for the balanced but before I get there a decent pre is called for.
PM to you.
Just a bit more currants to one side and then back in line with the pots.
Tanks Zen
got 4 new boards ready for etching tomorow for the balanced but before I get there a decent pre is called for.
PM to you.
have you possibility to steal/borrow/rape some bigger cones - to hear with that Fugly! amp ?
I'll not tell ya which breed of ancient spks is tool at PL
I'll not tell ya which breed of ancient spks is tool at PL
Please tell me more about ancient.
The times when I was getting paid to carry big speakers are long gone.
And mate with 76 Lowthers fitted troug living room wall in different country so...
Besides:
If it came from Zen it must be fertilizer not immediately evident but it will make things grow and prosper.
The times when I was getting paid to carry big speakers are long gone.
And mate with 76 Lowthers fitted troug living room wall in different country so...
Besides:
If it came from Zen it must be fertilizer not immediately evident but it will make things grow and prosper.
Fundamentally it does not make sense to have a 30%
AC variation in the Source-Rail voltages without having
some issue. First place to look is actual resistance value
of the Source resistance, and of course we are assuming
the output DC is near 0 volts at idle.
As to the sound, there is currently no fine understanding
of the correlation of sound quality to the potential
harmonic content. There's lots of "internet wisdom" on
the subject, but plenty of counter-examples.
😎
Nelson:
If the transconductances or Vgs of the mosfets and/or jfets were "grossly" mismatched, wouldn't that be enough to explain the source to rail voltage AC voltage variations?
Recently I have acquired both a Tek 465B scope and the means to make distortion measurements (an M-Audio Audiophile 192K, plus the Cordell Distortion Magnifier). The 2nd pair of F5 channels (which are in continual service) look good: better than .01% THD at 1KHz, 1 watt. As soon as I acquire parts for another power supply, I will make measurements of the first pair of channels, which have the "sweet" sound, but questionable FET matching.
If the transconductances or Vgs of the mosfets and/or jfets were "grossly" mismatched, wouldn't that be enough to explain the source to rail voltage AC voltage variations?
Recently I have acquired both a Tek 465B scope and the means to make distortion measurements (an M-Audio Audiophile 192K, plus the Cordell Distortion Magnifier). The 2nd pair of F5 channels (which are in continual service) look good: better than .01% THD at 1KHz, 1 watt. As soon as I acquire parts for another power supply, I will make measurements of the first pair of channels, which have the "sweet" sound, but questionable FET matching.
Hi Ihquam
I have the same sound card
I had not time to realy try out and mesure much so far
This is My firts Papa Amp and was to eagher to ear it plaiing.
On a loop back test I got quite a bit of noise on the 50 Hz
Is it same for you?
What way around?
Which software U use ?
I have Tru RTA and IMO much beter ARTA.
Can you share more on this regard please.
I have the same sound card
I had not time to realy try out and mesure much so far
This is My firts Papa Amp and was to eagher to ear it plaiing.
On a loop back test I got quite a bit of noise on the 50 Hz
Is it same for you?
What way around?
Which software U use ?
I have Tru RTA and IMO much beter ARTA.
Can you share more on this regard please.
