The XA200 currently uses Qty 16 times 40 wire ribbon cables
to connect the output stage. The XA160 uses 10.
to connect the output stage. The XA160 uses 10.
oh boy, I try to imagine how this looks like ! 
(shameless try to get a photo of the output stages from Nelson ... 😉 )
40 wires is like a harddisc IDE cable. You can make it a tube and strip all ends and solder them together on the tiny leg of a IRFP240 ... Still imagining how this all looks like...
This makes me doubt about my wiring strategy 🙁
Edwin
(shameless try to get a photo of the output stages from Nelson ... 😉 )40 wires is like a harddisc IDE cable. You can make it a tube and strip all ends and solder them together on the tiny leg of a IRFP240 ... Still imagining how this all looks like...
This makes me doubt about my wiring strategy 🙁
Edwin
As mentioned in the progress thead...................
By the way this is a bit off topic but its still progess, I tried to X the BOSOZ last night.
Gee what a change. Has anyone else done the conversion recently?
At the moment I'm evaluating dual CCS (Aleph style) in normal BOSOZ mode..
The short answer is if it ain't broken don't fix it.
That sound of the X for me was uwwweeee not sure that to say.
Condition: Using U/Balanced in, negtive input shorted. Balanced output.
The CCS Aleph front end set to 40ma dual CCS was good, but.....its a taste thing, there was more high frequency detail, although some how it lost that fluid...liquid nature.
The engagement was taken over by a more clinical sound...where's that nice eurphoric (spelling broken sorry) character gone....the BOSOZ trademark!.
I like accuracy but also balance and harmony......as the published design stand's it can't be faulted.
Somehow I think when Mr Pass sees a design from the centre of his mind " It is as it should be". The Man's just brilliant.
God.....we live in special time don't we Guys.
Stray from the path if you dare, but the nector may be missing.
Ian
PS In the end at least on my configuration (Aleph 2 /sans JBL Pro studio monitors) I don't need the extra detail...(I'm not running Vifa Ariels...please not that they are bad)
By the way this is a bit off topic but its still progess, I tried to X the BOSOZ last night.
Gee what a change. Has anyone else done the conversion recently?
At the moment I'm evaluating dual CCS (Aleph style) in normal BOSOZ mode..
The short answer is if it ain't broken don't fix it.
That sound of the X for me was uwwweeee not sure that to say.
Condition: Using U/Balanced in, negtive input shorted. Balanced output.
The CCS Aleph front end set to 40ma dual CCS was good, but.....its a taste thing, there was more high frequency detail, although some how it lost that fluid...liquid nature.
The engagement was taken over by a more clinical sound...where's that nice eurphoric (spelling broken sorry) character gone....the BOSOZ trademark!.
I like accuracy but also balance and harmony......as the published design stand's it can't be faulted.
Somehow I think when Mr Pass sees a design from the centre of his mind " It is as it should be". The Man's just brilliant.
God.....we live in special time don't we Guys.
Stray from the path if you dare, but the nector may be missing.
Ian
PS In the end at least on my configuration (Aleph 2 /sans JBL Pro studio monitors) I don't need the extra detail...(I'm not running Vifa Ariels...please not that they are bad)
macka said:
A little bit confused.
Which one is so negative?
X?
CCS?
Or both?
JH
PS. For your info. Mine has no X but CCSs and it works fo the unbalanced-in/balanced-out.
Sorry,
Just BOSOZ normal plus ccs :
The CCS Aleph front end set to 40ma dual CCS was good, but.....its a taste thing, there was more high frequency detail, although some how it lost that fluid...liquid nature.
I will listen to X BOSOZ again in the morning during Sunday School with and with out CCS and let you know.
Ian
Just BOSOZ normal plus ccs :
The CCS Aleph front end set to 40ma dual CCS was good, but.....its a taste thing, there was more high frequency detail, although some how it lost that fluid...liquid nature.
I will listen to X BOSOZ again in the morning during Sunday School with and with out CCS and let you know.
Ian
Hi Ian!
Can´t wait to read about your experiments with XBOSOZ and CCS´s.
I have done that too.
You can read about it here: http://www.diyaudio.com/forums/showthread.php?s=&threadid=3949&perpage=15&pagenumber=28 post #416
By the way, how did you apply X to the BOSOZ?
Can´t wait to read about your experiments with XBOSOZ and CCS´s.
I have done that too.
You can read about it here: http://www.diyaudio.com/forums/showthread.php?s=&threadid=3949&perpage=15&pagenumber=28 post #416
By the way, how did you apply X to the BOSOZ?
Ciao Henrik and Paolo(😉 ) and all:
My understanding is that Ian use the Aleph current source at the drain resistors position, at 40mA each . This need the feedback ,of course , like the Aleph P 1.7 .
The BOSOZ trade mark:
I agree with you Ian; BOSOZ has that wonderful liquid caracter and I love it. Adding feedback as usual is a matter of taste , and I find I like a preamp without feedback between the music source and the amp.
My Aleph X progress report: not tried any different input/ground resistor yet and waiting for better parts just to rise a bit the rails voltage (up to 25V) I'm still enjoing the Zen V4 at 45volt rail.
The original Aleph X I built has only +-15volt rails and I do not like it in a particular way.I also need bigger heat sinks , so Zen V4 is the favourite NOW.
One channel of the 2 AlephX do a strange thing: when the volume is high it tends to lose its dc absolute point and also between the speakers , it go to 5 volts ,the woofer go to the floor🙂clown: ) and the music stops.
Then is necessary or put off the rails or disconnect the speakers ,or the use of a capacitor for stop the dc trough the woofer. Assuming that the input is cap coupled and apparently everything in the circuit is ok, can someone explain why this thing happens?
😎
My understanding is that Ian use the Aleph current source at the drain resistors position, at 40mA each . This need the feedback ,of course , like the Aleph P 1.7 .
The BOSOZ trade mark:
I agree with you Ian; BOSOZ has that wonderful liquid caracter and I love it. Adding feedback as usual is a matter of taste , and I find I like a preamp without feedback between the music source and the amp.
My Aleph X progress report: not tried any different input/ground resistor yet and waiting for better parts just to rise a bit the rails voltage (up to 25V) I'm still enjoing the Zen V4 at 45volt rail.
The original Aleph X I built has only +-15volt rails and I do not like it in a particular way.I also need bigger heat sinks , so Zen V4 is the favourite NOW.
One channel of the 2 AlephX do a strange thing: when the volume is high it tends to lose its dc absolute point and also between the speakers , it go to 5 volts ,the woofer go to the floor🙂clown: ) and the music stops.
Then is necessary or put off the rails or disconnect the speakers ,or the use of a capacitor for stop the dc trough the woofer. Assuming that the input is cap coupled and apparently everything in the circuit is ok, can someone explain why this thing happens?
😎
Here are the results of my measurements for the AX with single output device per side, with 0.22 ohms rource resistors. Everything was readjusted at each voltage before measuring, the AC gain resistor was recalculated and replaced approriately to produce the 50% current gain. My circuit does not have protections on the gain mosfets.
I ended up measuring the output voltages right about .5 V from clipping for +/- 15V rails and for +/-20 V rails on 8 ohms load, only. The input was se, oh yeah, I forgot to measure the gain but who cares? I used a differential probe to measure the outputs...what else am I forgetting in my experimental section?? 😉
The graph shows the power and the output voltage. Extrapolating to Nelson +/- 30VDC rails gives 220 W vs. 200W declared by Nelson. 10% error on a two point fit is more than good enough and suggests that my measurements of ~27 W at 15 VDC and ~72W at 20V rails are reasonable.
The agreement with the calculation spreadsheet (Berekening.xls) is very poor for the 15V (~25% discrepancy) rail but it becomes better at 20 V (~13% dicrepancy) rails to suggest that there are elements of non linearity at low voltage that ar not properly being accounted for in the calculation.
I ended up measuring the output voltages right about .5 V from clipping for +/- 15V rails and for +/-20 V rails on 8 ohms load, only. The input was se, oh yeah, I forgot to measure the gain but who cares? I used a differential probe to measure the outputs...what else am I forgetting in my experimental section?? 😉
The graph shows the power and the output voltage. Extrapolating to Nelson +/- 30VDC rails gives 220 W vs. 200W declared by Nelson. 10% error on a two point fit is more than good enough and suggests that my measurements of ~27 W at 15 VDC and ~72W at 20V rails are reasonable.
The agreement with the calculation spreadsheet (Berekening.xls) is very poor for the 15V (~25% discrepancy) rail but it becomes better at 20 V (~13% dicrepancy) rails to suggest that there are elements of non linearity at low voltage that ar not properly being accounted for in the calculation.
Attachments
I don't understand how the loss of absolute dc point would cause DC on the speakers, I put my amp under all kinds of abuse and the differential dc offset is nailed at 10-30mV. I did find absolute DC changes between low power and high power in the order of maybe 0.5V-1V but you should never see that on the speaker.
Together with the gain, the sonic 'signature' of the amp is going to depend ALOT on the input resistor value. After you solve the dc problem you should definitely play with that. 😉
Happy Birthday Aleph-X
Celebrations are in order, This thread is one year old today. Grey posted the 1st post 25 May 2002.
What a lot has been accomplished in one year!!!
Cheers, Adrian
Celebrations are in order, This thread is one year old today. Grey posted the 1st post 25 May 2002.
What a lot has been accomplished in one year!!!
Cheers, Adrian
grataku said:
Are you talking about series resistors or resistors to ground? And what value of feedback resistor did you prefer?
MY INPUT...
Hi,
In my book that's the resistor at the input of the amp/preamp, namely the shunt R between hot and neutral...
Semantics again perhaps?😉
Hi,
In my book that's the resistor at the input of the amp/preamp, namely the shunt R between hot and neutral...
Semantics again perhaps?😉
Okay,
Here is something odd.
I am just measuring the conditons of bias for the BOSOZ with normal tail resisters 750 x 2, the bias is only 34.4 ma?
I wonder why, the vgs of my matched 610s was about 3.96 v
Ian
Here is something odd.
I am just measuring the conditons of bias for the BOSOZ with normal tail resisters 750 x 2, the bias is only 34.4 ma?
I wonder why, the vgs of my matched 610s was about 3.96 v
Ian
Peter, I have a predisposition for the low gain arrangement with the 10 k to gnd instead of the 68K. I have 100K and 10pafs in the feedback.
In all my playing around with the circuit the only signs of instabilty were shown after adding the bypass caps that are used on the aleph and by having the absolute offset too far from 0 the oscillation disappears by adjusting the CCS trimpot.
The CCS adjustment seems to be getting somewhat narrower at higher voltage ie it's easier to get the circuit to misbehave at higher rails.
I have been developing this crazy idea in my head that a higher voltage voltage reference, namely the 9.1 V instead of the 6. V of the LMXXX would facilitate the tuning aspect at higher rail voltage. Crazy to think that Nelson and Grey may have had it right the first time around, isn't it? 😉
In all my playing around with the circuit the only signs of instabilty were shown after adding the bypass caps that are used on the aleph and by having the absolute offset too far from 0 the oscillation disappears by adjusting the CCS trimpot.
The CCS adjustment seems to be getting somewhat narrower at higher voltage ie it's easier to get the circuit to misbehave at higher rails.
I have been developing this crazy idea in my head that a higher voltage voltage reference, namely the 9.1 V instead of the 6. V of the LMXXX would facilitate the tuning aspect at higher rail voltage. Crazy to think that Nelson and Grey may have had it right the first time around, isn't it? 😉
I browsed this thread but couldn't find an answer for my problem. I am building the aleph--x using the Hifizen Aleph-X 1.0 boards and the Grollins spec (so no jfet and things like that). Except for the following things:
I used IRFP240 mosfets and bc550c instead of the MPSA18. Also I have changed r12 & r34 in 820 ohm to compensate for the other output devices. Edwin stated that he used 793 ohm to get a current-gain of about 56%. The original 1,2k gave 30-35%.
Oke now the question; if I fire up the beast I get a rail of 16 volts that's dropping to about 15,6. When I measure the voltage over the sourceresistor R5 (0.22 ohm) I measure 0.65 Volt. This is with the trimmer VR1 and VR3 at maximum resistance. (used 100k Bournes)
Before that I burned my source resistors in the other channel during warming up. I just wanted to measure when things got hot
. I waited to settle things down, but apparently that was to much for the resistors. (4 watt MOX)
So my question is how can I get the bias down,
1) change the trimmer?
2) change some resistors (maybe r31 ?)
3) or is there something else wrong.
P.S the "good" channel stabelised around 0.63 Volt with an absolute off-set of 0.04 volt without changing VR1. But the bias is still to high
I used IRFP240 mosfets and bc550c instead of the MPSA18. Also I have changed r12 & r34 in 820 ohm to compensate for the other output devices. Edwin stated that he used 793 ohm to get a current-gain of about 56%. The original 1,2k gave 30-35%.
Oke now the question; if I fire up the beast I get a rail of 16 volts that's dropping to about 15,6. When I measure the voltage over the sourceresistor R5 (0.22 ohm) I measure 0.65 Volt. This is with the trimmer VR1 and VR3 at maximum resistance. (used 100k Bournes)
Before that I burned my source resistors in the other channel during warming up. I just wanted to measure when things got hot
. I waited to settle things down, but apparently that was to much for the resistors. (4 watt MOX)So my question is how can I get the bias down,
1) change the trimmer?
2) change some resistors (maybe r31 ?)
3) or is there something else wrong.
P.S the "good" channel stabelised around 0.63 Volt with an absolute off-set of 0.04 volt without changing VR1. But the bias is still to high