| kristijan-k |
The preamplifier is Balanced Zen Line Stage and it is installed in well modified enclousure of Technics preamplifier SU-C 1000 mark2.
Balanced outputs are not in use because it is still under construction (input/output selector without tape monitor switches).
Sigma 6 is printed because it have 6 inputs.
Sony minidisc is also well facelifted for more audiophile look. |
|
|
| fcel |
| Kristijan: On your web site link, you have a circuit diagram of Aleph 5. Correct me if I'm wrong but shouldn't the resistors at the source of the IRF244 transistors be tied together? |
|
|
| BrianGT |
I believe the circuit is correct. Look at the Aleph 3 service manual for a schematic without the X3, and the Aleph 3 has two output devices in parallel, and are setup the same way that kristijan did his.
--
Brian
gte619j@prism.gatech.edu |
|
|
| mefinnis |
Brian and Kristijan are absolutely correct.
Each FET plus it's source resistor should be independent. The sensing circuit only need to look at one of these because they are perfectly balanced.
cheers, mark |
|
|
| kristijan-k |
You are wrong.
The circuit diagram of Aleph 5 amplifier on my website are correct.
The circuit and all PCBs on my website are tested several times
and they all work perfect.
Kristijan Kljucaric |
|
|
| fcel |
Brian,
As you know, I'm planning on building Aleph 2. The circuit diagram shown on Kristijan's web link caught my attention because I want to compare the differences between Aleph 2 and Aleph 5.
I've check out the circuit diagram of Aleph 5 on the Pass Labs web site and it sure looks very similar to Aleph 2, especially at the outputs stage. If what was shown on Kristijan's web link is correct, does it mean that the resistors at the source of the output transistors for Aleph 2 should NOT be tied together either? I wanted to know because I'm going to be building the Aleph 2 in the near future.
There are a couple of difference for Aleph5 that I can see. Example, C7, C10 are connected differently. There are four 0.47 ohms at the output for Aleph 5 while there are six 1 ohm for Aleph 2. And then there are also some other different values of capacitors and resistors for Aleph 5. I'm assuming that X3 IRF244 for Aleph 5 is correct. I read that the X3 for Aleph 4 is not correct initially as reported on Mark's web site. |
|
|
| hifi |
| one error i see is the led/resistor shoudl be connected between the + and - |
|
|
| kristijan-k |
PCBs for ALEPH 2 amplifier will also be available on my website:
( http://web.vip.hr/pcb-design.vip ), and it will have 6 output devices with their current sources, like Mr.Pass used his original
ALEPH 2 amplifiers.
PCBs will be available after 22.IV.2002 and they use similar layout like Aleph 5 amplifier on my website, but dimensions are a little bigger and all parts are also located on one PCB.
Kristijan Kljucaric |
|
|
| fcel |
| Kristijan: When can the circuit diagram of Aleph 2 be posted on your web site? I would very much like to see the connections of the six output transistors. Thanks. |
|
|
| kristijan-k |
| In a couple of days. |
|
|
| mefinnis |
| quote: | Originally posted by hifi
one error i see is the led/resistor shoudl be connected between the + and - |
Alas, no, kristijan is again correct.
You could put the LED between the rails, but Nelson did not he placed it across the current source. Please check the original diagram ;)
cheers, mark
PS: I am not on a commission from kristijan ! |
|
|
| GRollins |
Bear in mind that the output line is at ground potential when there's no signal. Thus, for all intents and purposes, the LED sees one rail's worth of voltage (assuming no signal).
Note that I chose to run the LED on my Aleph from rail-to-rail with two current-limiting resistors. Yes, I could do one with twice the value. I just liked the visual symmetry of having one resistor per rail. It bleeds both rails down equally at shutoff.
Grey |
|
|
| promitheus |
| I was always wondering why this led is connected there. Does it have any purpose ? |
|
|
| wuffwaff |
Hi Promitheus,
itīs there so you know if your ampīs on or not:D
william |
|
|
| kristijan-k |
fcel,
The circuit diagram of Aleph 2 amplifier is a little too big to be posted on this forum, but it is posted to the website http://web.vip.hr/pcb-design.hr
There you can also see the PCB component layout.
Kristijan Kljucaric |
|
|
| fcel |
Brian,
Kristijan have shown -ve of C9 (220uf) connected to +ve output as per spec from the Pass Labs service manual. You have shown yours connected to the emitter of transistor MPSA18 as documented in the other thread. I have been meaning to ask you .... or anybody ...... how the circuit would operate differently from the 2 different ways of connections ..... heat wise, sound wise, speaker sensitivity wise, etc .... I'm trying to understand this circuit a lttle bit more. |
|
|
| mefinnis |
| quote: | Originally posted by promitheus
I was always wondering why this led is connected there. Does it have any purpose ? |
As opposed to Wuffwaff's helpful comment re the amp being on (I think promitheus got that one!) I wondered this myself.
This is the reason that I installed a LED for each channel in my Aleph4. Not being an EE I could not guarantee Nelson hadn't used it in some subtle way as a part of the current source .... which is what I suspect promitheus was really asking, and I would like to ask as well.
Can anyone clarify this?
Otherwise I would go for Grey's approach and have just 1 LED for the power supply rails ...... I only need 1 to know the amp is on, I'm quick like that ;)
cheers, mark |
|
|
| mefinnis |
| quote: | Originally posted by fcel
Kristijan have shown -ve of C9 (220uf) connected to +ve output as per spec from the Pass Labs service manual. You have shown yours connected to the emitter of transistor MPSA18 as documented in the other thread. |
WARNING - Be very careful with Neslon's schematics!
The original circuit does not show C9- connected to the output, it connects to Q5e / C7 / Q18-20d / Rs of the current source / the infamous LED / R22-25.
Nelson's typography is "joins are shown as broken lines", however he disobeys this himself where C10-R19 crosses Q5b-R20, which is a join and should have been broken.
The circuit as shown, I believe, is correct.
Then BrianGT says:| quote: | | How would one keep the Aleph 2 cool, with all of the mosfets so closely spaced together? That would mean that one heatsink would dissipate 300W. That seems pretty difficult, unless you are using active cooling. |
I too would be happier with greater spacing between the FETs, the center fellas are gonna have a hot time!
cheers, mark
PS: And I'm still not on a commission |
|
|
| fcel |
Mark,
You indicated the the original circuit does not show C9- connected to the output ............. but the latest circuit diagram from Pass Labs does shows C9- connected to the output as well as Kristijan circuit diagram in this thread. Is Nelson Pass aware that it's shown that way. As discussed in the other thread, Brian, Grey , Wayne and probably others do know what's the correct connection. I don't know how they know! Should it be corrected so that some other poor guy like me don't have to go through this exercise again? It has been discussed that it does not make any difference but I'm curious as to why it does not make any difference. |
|
|
| BrianGT |
I asked Nelson about this C9 business, and he said that it does not matter of the placement of the capacitor.
I just followed the way that the majority of the aleph manuals, gray and the patent, did it in their circuitry.
--
Brian
gte619j@prism.gatech.edu |
|
|
| mefinnis |
| quote: | | ..... but the latest circuit diagram from Pass Labs does shows C9- connected to the output as well as Kristijan circuit diagram in this thread. |
Given the circuit diagrams have changed over time, I went back and re-downloaded the PDF for the Aleph5.
This is PL33FE01 of 09/23/96.
I'm confused. I cannot see where you get a connection from C9- to the +Output. Again, it connects to the junction of the current source resistors/drain of the output FETs, immediately before the output resistor quadruplet - and to the emitter of Q5, as always. This is also how I read Kristijan's circuit diagram, BTW.
Can you e-mail me a copy of the diagram to which you are referring, or post it here.
cheers, mark |
|
|
| fcel |
| Mark: I was talking about the Aleph 2 circuit diagram. If you look at the PDF file of Aleph 2 on Pass Labs web site, you'll see that C9- is connected to the + output. Same on Kristijan web site. I brought it up because even though it's shown that way, everybody seems to built it with C9- connected to the emitter of MPSA18 - just like in Aleph 4 or 5. And I was just questioning why and how they know. Brian said he asked Nelson already and the reply is connect C9- like in Aleph 4 or 5. |
|
|
| mefinnis |
Curiosity got the better of me .... I just went back and downloaded all of the service manuals.
Now ..... I'll grant you the Aleph2 diagram (PL30R0 - 12/1/96) does show C9- connected to the output!
Further to Brian's comment from NP, which side of a 0.08ohm resistor (0.047/6) you take this feedback is likely immaterial.
Sorry to be a "stick in the mud", but I get obsessional about some things :)
cheers, mark |
|
|
| mefinnis |
Amazing how when 2 people are looking at different things they see a different perspective .....
As Nelson says, from the circuit operation it would make no difference. All other circuits (A5,4,1.2) are the same so I would go with this, personally.
If you have made your PCBs as per the A2 then don't worry and just go ahead.
Nelson has had the odd problem with "borrowing" circuit diagrams, ie. instead of re-drawing the whole thing he starts with a "sister" circuit and amends the fine details ..... this was the genesis of the now infamous "x3" versus "x6" mishap in the A4 circuit. I ain't gonna pick on him too much for this ;)
cheers, mark |
|
|
| BrianGT |
I especially like how the connecting nodes of the circuit in the schematics are not labeled with dots. The only one which has dots is the Aleph 4 schematic (if I recall correctly).
--
Brian
gte619j@prism.gatech.edu |
|
|
| fcel |
Mark: I'm glad you agreed with me on this one!
Brian: It's good to know there are dots shown on Aleph 4 circuit! |
|
|
| kristijan-k |
Hello to everyone,
I received several e-Mails on C9 issue and it seems that some peoples are little confused.
The C9 issue is not that important like most people think and you shouldnt be bordered with that. The C9 can be connected on both ways stated in previous threads without any problem.
The only difference is in .47R/6 => 0.078 Ohms and in this case it will not make any difference.
Also, last year when I made my first PCBs prototypes, I was also wondering myself why Mr.Pass connected C9 in that way, then
I made several tests and measurements(q.current,power,distortion,freq.response) on both ways of connection, and results were identical.
There is no way for sonic difference, and after all the original Pass Labs Aleph 2 amplifiers used identical circuit diagram like it is originally posted by me,and that is the main reason why I lefted the circuit unchanged, like Mr.Pass originaly designed it.
For sonic difference you should be more worried about speaker quallity and sonic characteristics of your room and no for well proven and excellent sounding design, at least at my opinion.
Kristijan Kljucaric |
|
|
| strobo |
Does anyone know where to find IRF 244 transistors ?
What other types (except IRFP 240) will work the best for substitution ? |
|
|
| mefinnis |
IRFP244s ..... obviously ;)
cheers, mark |
|
|
| strobo |
Hi,
Is it possible to use Non-Polarised electrolitic
capacitors (220 uF) on Aleph 5 amplifier, instead regular ones?
Does anyone tried this ? |
|
|
| wuffwaff |
Hi Strobo,
of course itīs possible but why?
william |
|
|
| strobo |
Thanks wuffwaff,
Is there any advantage, to use Non-Polar electrolitic capacitors in Aleph 5 amplifier instead Polarised capacitors ?
Also, what is the difference between IRF 244 and IRFP 244 mosfets ? |
|
|
| wuffwaff |
Hi Strobo,
I donīt think there an advantage using non ploar capacitors in the aleph5 but if youīre nopt shure just try and listen;)
As for the IRF244 and IRFP244 the latterīs a TO247 package and the other one a TO-3.
william |
|
|
| Karen |
| T03 are the 244's and T03P, or T0247 are 244p. It's the packaging, p for plastic. |
|
|
| strobo |
Hi,
I tried to find IRFP 244 at my local shops, but I didn't have luck.
Also, they not have IRFP 240.
Is there some similar devices that will work for substitution ?
I will use them for Aleph 5 amplifier.
---
Strobo |
|
|
| strobo |
Hi Karen,
It seems that I not only have the problem with the finding IRF 244 transistors.
e-Mail link that you posted don't work.
I tried several times, but every time It was returned to me.
But, here it is:
Hello,
Thank you for reply on my question on the diy forum.
I would like to build Aleph 5 Amplifier, but I have problem with finding IRF 244 transistors.
Is there some similar devices that will work for IRF 244 substitution ?
What about IRFP 250 - I can buy them in my local shop, but a friend of mine told me that amplifier would have much more distortion with this device, is this true ?
How much higher distortion will be, compared to IRF 244 ?
Thanks for your time,
Strobo
>
>
>This Message was undeliverable due to the following reason:
>
>Each of the following recipients was rejected by a remote mail >server.
>The reasons given by the server are included to help you >determine why
>each recipient was rejected.
>
> Recipient: <help@passlabs.com>
> Reason: 5.1.1 <help@passlabs.com>... User unknown
>
> |
|
|
| harvardian |
Strobo,
How many do you need (IRFP240) or IRFP244?
Where are you located?
Best Regards,
Dale |
|
|
| strobo |
Thanks Harvardian,
I allready ordered 50 x IRFP 240.
It seems that a many peoples used IRFP 240 instead IRF 244, and they didn't have any objections, so I will try the same way.
Is 50 pcs will do for 24 mached devices, or should I order more ?
How accurate they should be matched ?
---
Strobo |
|
|
| strobo |
Also, what type of isolators will work best for output transistor / current sources on Aleph 5 amplifier, mica or silicon rubber ?
Is it necessary to use silicon paste with rubber type ? |
|
|
| Dornier |
I tried both types, and I can say that the mica types are probably better, but the thermal grease must be used.
Silicon rubber types can be used without thermal grease. |
|
|
| kristijan-k |
Hello,
For high heat dissipation I would recommend you to use mica type isolators with the silicon thermal paste.
They are a little more messy, but I think that they are better than
rubber type.
If using the silicon rubber type, you must not overtight the devices
with the screws, as the isolator will start to distort.
Regards,
Kristijan Kljucaric |
|
|
| chorei |
hi,
can the irfp 250 or the irfp 260 be used for the aleph 5 amplifier ?
if can, what type will work best ?
anyone have some experience with this devices ? |
|
|
| Dornier |
I tried the IRFP 240 and they work ok.
Remember, they all should be matched.
I also wonder if the IRFP 250 can be used. |
|
|
| HarryHaller |
The LED is there to show that the amp is powered up. It is most likely connected to the amp output since ground does not connect
to the PCB that it is mounted on directly. It would have required
another wire from the Main PCB to the output PCB to connect the LED to ground. Nelson saved a wiire and two solder joints and made the trace routing a little simpler by not having to bring ground to the output PCB. It will not affect the operation of the circiut being wired in this manner. Another great audio mystery solved. (Reply to question on first page of thread)
H.H. |
|
|
| AudioFreak |
| I would not advise that you use IRFP250/260 as due to the package type, thermal dissipation is limitted and input capacitance is too high ... much better to use multiple IRFP240's in parallel as for around the same input capacitance, you can dissipate alot more heat. |
|
|
| Dornier |
hi,
anyone know what should be the minimum power rating of the .47 R output resistors and the zener diodes on the aleph 5 amplifier ?
Dornier |
|
|
| JasonL |
| Hey on your sight the boards for the aleph 5 they are blue do they come blue or are they a difrent colour can you post a pic of that the final out come is ?? Please |
|
|
| kristijan-k |
Hello JasonL,
The all PCBs that can be found at http://web.vip.hr/pcb-design.vip , are made of FR-4 fiberglass material with Cu-50 mikron + Pb track overlay (tinplated), laser drilled, with two sided blue soldermask (instead of green), and with white component overlay, like it is showed on the next photos.
Regards,
Kristijan Kljucaric |
|
|
| kristijan-k |
| Component side |
|
|
| JasonL |
THOSE are some nice boards i see that you have taken your time to get them designed properly and nicly layed out.. i will be perchasing some i just have to wait till i sell my yamaha amp as i pormmised in my email i will be getting the pre-amp and 2 x aleph 5 boards.. no one still hasnt answered my question about cooling.. Can i use a fan to keep the heatsinks cool i dont know if my heat sinks will be good for my aleph 5 but i believe they willl if you need a pic ill post it or email it to you ..
( kristijan-k )
Thanks jason |
|
|
| Peter Daniel |
| Nothing wrong with using a fan. |
|
|
| chorei |
Whoooow, Kristian did some realy excellent work with those blue PCBs.
I wonder, what software is used to design them to the state like this ?
I tried IVEX, but the layouts are not even close to the this PCBs. |
|
|
| kristijan-k |
Hello Chorei,
I used the PROTEL Version 2.7.1 for all PCBs.
Also, the good results are possible even with the IVEX.
Regards,
Kristijan Kljucaric |
|
|
| chorei |
hi,
i checked and found out that the protel 2.7.1 is very old version.
why it is used instead new version ?
is there any catch ?
any other good software for PCB designing ? |
|
|
| Coulomb |
Hi Kristijan, could you tell me what the hole centres for mounting the fets are on your Aelph V PCB and Ver II of your Aelph II PCB (3 pc. Set)?
I am trying to see if they will fit in an existing chassis before I order the boards.
Thanks
Anthony |
|
|
| JasonL |
can i help in any way coulomb?? i doo have them boards
j' |
|
|
| kristijan-k |
Hello,
Chorei,
The Protel 2.7.1 is much cheaper than the newest version, and the final results are the same.
You can also use the Tango, Eagle, P-CAD ....
Coulomb,
The spacing on Aleph 5 , drain to drain, is 24,5 mm (0,9683 in).
The spacing on Aleph 2 - V2 (3 PCB set), drain to drain, is 43,5 mm (1,7193 in).
Also, the dimensions of all PCBs are stated on the website.
If I can be of further assistance to you, please feel welcome to contact me again.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
|
|
| JasonL |
nice i stil have my protel 98 with my spacial version both... but till this day i still have not figured out how to make a pcb.. id like to though..
J' is there any one that can help me with the protel 98... |
|
|
| mpopovics |
| quote: | Originally posted by JasonL
J' is there any one that can help me with the protel 98... |
Open the Protel help, and follow the tutorial. It is really helpful, and easy to learn, how to use the SW.
It is teach you step-by-step, how to create your PCBs.
I did it also. |
|
|
|
