Revision of Very Best Amplifier ... 2015

Jump to Latest
obiwankenobi

obiwankenobi

Member
Joined 2011
dpsmedical.com.ar
#1
Dear friends:

Here is a new thread.

Purpose: revision of the existing thread
http://www.diyaudio.com/forums/solid-state/174468-very-best-amplifier-i-have-ever-heard.html

I will ask this with total kindness:

The mentioned thread was very confusing for many members like me. Of course it is full of good knowledge and wise people. But many members are fond of selfishness and some others have been mocking arround.

Please be so kind to contribute with an open mind, avoiding mysteries and sharing knowledge, with a real hobbyst point of view. That's is what a forum stands for: help each other and share good information.

Lastly, please upload schematic diagrams and try to clearly explain what you think and/or suggest.

I bought 2 original boards that work with just 4 MOSFET transistors as power output (not 3). I suggest to start with this first schematic and try to stick to this.

I suggest to order this first part and then we could jump to many other ideas and circuit revisions. But I kindly ask not to fall in the other's forum disorder .

I am uploading the original schematics and board drawings as NagysAudio provided.

Any suggestion is very welcome 🙂
Roberto
 

Attachments

  • Mimesis 3 Layout 11.JPG
    Mimesis 3 Layout 11.JPG
    586.2 KB · Views: 5,804
  • Goldmund Mimesis 3 Final Protection Circuit Schematic 2.jpg
    Goldmund Mimesis 3 Final Protection Circuit Schematic 2.jpg
    164.8 KB · Views: 2,572
  • Goldmund Mimesis 3 Final Protection Circuit Schematic 1.jpg
    Goldmund Mimesis 3 Final Protection Circuit Schematic 1.jpg
    262 KB · Views: 5,500
  • Goldmund Mimesis 3 Final Schematic.JPG
    Goldmund Mimesis 3 Final Schematic.JPG
    500.2 KB · Views: 5,947
  • Goldmund Mimesis 3 Final Power Supply Schematic.jpg
    Goldmund Mimesis 3 Final Power Supply Schematic.jpg
    327.9 KB · Views: 5,372
  • Mimesis 3 Layout 55.JPG
    Mimesis 3 Layout 55.JPG
    452.2 KB · Views: 5,194
#2
Some useful information (kindly sent to me by NagysAudio by email):

Here's a complete list of all the MOSFETS and equivalents that can work in this amplifier:

Plastic Case:

Hitachi 2SK1058/2SJ162 (Obsolete)
Renesas 2SK1058/2SJ162
Hitachi 2SK1057/2SJ161 (Obsolete)
Renesas 2SK1057/2SJ161
Hitachi 2SK1056/2SJ160 (Obsolete)
Renesas 2SK1056/2SJ162
Exicon ECX10N16/ECX10P16
Exicon ECX10N20/ECX10P20
Magnatec BUZ900P/BUZ905P
Magnatec BUZ901P/BUZ906P
Magnatec BUZ902P/BUZ907P
Magnatec BUZ903P/BUZ908P

Metal Case:

Hitachi 2SK135/2SJ48 (Obsolete)
Hitachi 2SK134/2SJ49 (Obsolete)
Hitachi 2SK133/2SJ50 (Obsolete)
Hitachi 2SK176/2SJ56 (Obsolete)
Hitachi 2SK175/2SJ55 (Obsolete)
Exicon ECF10N16/ECF10P16
Exicon ECF10N20/ECF10P20
Magnatec BUZ900/BUZ905
Magnatec BUZ901/BUZ906
Magnatec BUZ902/BUZ907
Magnatec BUZ903/BUZ908

As you can see, there are MANY choices out there. All are fantastic MOSFETS and will work 100% in the Goldmund schematic.

NOTE: THE IRF HEXFETS WILL NOT WORK IN ANY GOLDMUND SCHEMATIC. PLEASE BE CAREFUL!

Attached is a copy of the schematic I made trying to put the circuit all together. Needs revision and I hope that somebody could help and tell if the protection circuit is correctly drawn.

Also some links to required parts and its vendors.

Mr. Steve LaGaisse from RFparts provided the 2N5566 JFET's
email: Steve <Steve@rfparts.com>
I am reproducing his quote here:

We can only offer the 2N5566 from our stock. Price is $7.95 each for 50 pieces.

Thank you,
Steve LaGaisse
Steve LaGaisse
RF Parts Co
ph 760-744-0700 ext.316
fax 760-744-6030
Home page
Click to expand...



SEMELAB BUZ900 N CHANNEL MOSFET, 160V, 8A, TO-3
BUZ900 - SEMELAB - N CHANNEL MOSFET, 160V, 8A, TO-3 | Newark element14 US

SEMELAB BUZ905 P CHANNEL MOSFET, -160V, 8A, TO-3
BUZ905 - SEMELAB - P CHANNEL MOSFET, -160V, 8A, TO-3 | Newark element14 US

BD249
Search Results | Newark element14 US

MULTICOMP BD250C BIPOLAR TRANSISTOR, PNP, -100V, TO-247
BD250C - MULTICOMP - BIPOLAR TRANSISTOR, PNP, -100V, TO-247 | Newark element14 US

Bc182
Transistors - Bipolar (BJT) Single Product List | Semiconductors - Discretes | Newark element14 US

JTN1AS-PA-F-DC24V - RELAY:
JTN1AS-PA-F-DC24V Panasonic Electric Works | 255-1720-ND | DigiKey

CAP ALUM 10000UF 63V 20% SNAP:
ECO-S1JA103EA Panasonic Electronic Components | P7492-ND | DigiKey

CAP ALUM 220UF 160V 20% RADIAL:
EEU-EE2C221S Panasonic Electronic Components | P13627-ND | DigiKey

CAP ALUM 150UF 63V 20% RADIAL
EEU-FC1J151 Panasonic Electronic Components | P10344-ND | DigiKey

FUSE GLASS 6.3A 125VAC 5X20MM
023306.3MXP Littelfuse Inc | F3634-ND | DigiKey




Also Norbert (NagysAudio) sent this to me:

Hi Roberto,

- Toshiba 2SK134/2SJ49 = Magnatec BUZ900/BUZ905, or BUZ901/BUZ906 (available at Newark, Farnell, eBay, etc.)
- MPSA93/MPSA43 = MPSA92/MPSA42 (available at Newark, Mouser, Farnell, DigiKey, eBay, etc.)
- BD250C/BD249C (available at Newark, Farnell, eBay, etc.)
- BC546B (available at Newark, Mouser, DigiKey,eBay, etc.)
- BC182B (available at Mouser, eBay, etc.)
-2N5565 = 2N5564/2N5566 (available at eBay and a bunch of other places from China online) also, the 2N5566, last I've checked, is available at Home page, you can contact Steve Lagaisse at 760-744-0700 ext. 316 to order them.
- BC556B = (available at Newark, Mouser, DigiKey, eBay, etc.)
- BC449 = MPSA06/BC546B (available at newark, Mouser, DigiKey, eBay, etc.)

This is the complete transistor reference list for the Goldmund Mimesis 3 amplifier. I won't include another one, so please print this one out. The hardest part to find is the 2N5564/2N5565/2N5566 dual j-fet, as they have no equivalents. But if you do some searching online, you should be able to come up with a few more sources than the ones I've listed above.

The MOSFETS you'll have to match. I cannot help you there as I do not sell any parts, nor have any of these MOSFETS in stock myself. You might have to order a few extra ones in case they don't match up too well. If you need the correct procedure on matching MOSFETS, please do a search online, there are hundreds of references.

Everything else you should be able to easily find on Newark, Mouser, DigiKey, Farnell, eBay, etc.

For heatsinks, my favorite place to purchase from is Extruded Aluminum Heatsinks from HeatSinkUSA

My favorite toroidal transformers are the Avel Lindberg. You can talk to Melanie Roman there, she's a very pleasant person to deal with.

Please understand, this is a solid state amplifier and unlike a tube amplifier, it requires a good understanding of electronics in order to build it. After you've finished it, the amplifier should be tested for oscillations. Depending on your grounding scheme, the length of input/output wires, chassis, board orientation, etc. you might have to play with the small capacitor values (4.7pF, 8.2pF, 10pF, 47pF, etc.), or even strategically add new ones.

I will supply you the complete original schematic for the Goldmund Mimesis 3 amplifier and the parts layout for the PCB boards. Unfortunately, everything else will be up to you to figure out and my help will be very limited. If this is acceptable to you, I'll get the boards out to you tomorrow morning. If not, I can send you a refund. There are no returns/refunds once the boards have shipped.

Regards,
Norbert
Click to expand...

I will write a resume of some usual questions about this project in my next post.

Cheers
Roberto
 

Attachments

#10
Alex, I assume you must have a set of different PCB designs dating right back to 2010 to the latest one you posted on 2nd December? It would be extremely useful if you could post each design in turn with accompanying schematic and brief change log of what has been altered and why (and if it's tested and working). If you cannot remember why all changes were made it would still be valuable to have the change list with accompanying schematic.

Once we have identified all the changes we can verify these are correct through to your most recent design. You could maybe make seperate posts for each revision and edit and add accordingly as we work through the changes. This would give some structure to the project and everyone can refer to this as a base reference for each version they have.

Nikosokey, it would be very helpful for all of us if you would do a brief write up with your schematic attached (so we can reference this to one of Alex's uploads). If you could explain any changes or problems you faced and how you solved these (briefly) this would be an excellent resource.

Likewise if would be useful if anyone who has built a working revision could do the same and we'll start to have a working structure for all persons 🙂
 
Last edited:
  • Thank You
Reactions: Silvio Novais
#11
KatieandDad said:
There are some errors or omissions on the PCB tracks, for example, only one side of the relay coil is connected.
Click to expand...

KatieandDad please are you talking about the PCB layout of post #1 ?
Alex mm , did you designed this PCB of post #1 ?

I would like to kindly ask everybody to stick to the original model of 2 power output MOSFET's , because this is the reason why this thread was started. Please be so kind to read the #1 post. The idea is to put order for those who have this PCB model, despite we can later get into details for changing it to a better version.

Thank you very much.
 
#12
smatteo said:
Hello

I want to build and amplifier of this project having some paired 2SK1058+2SJ162.
I would like to buy the pcb release for 2 or 3 pairs of final mosfet, who may help me?
thanks in advance

matteos
Click to expand...

Hello matteos, we are trying to put order on the 2 pair output transistor model first although I think that somebody has designed a 3 pair version and could possibly sell you the board.
 
#13
matt09 said:
Alex, I assume you must have a set of different PCB designs dating right back to 2010 to the latest one you posted on 2nd December? It would be extremely useful if you could post each design in turn with accompanying schematic and brief change log of what has been altered and why (and if it's tested and working). If you cannot remember why all changes were made it would still be valuable to have the change list with accompanying schematic.

Once we have identified all the changes we can verify these are correct through to your most recent design. You could maybe make seperate posts for each revision and edit and add accordingly as we work through the changes. This would give some structure to the project and everyone can refer to this as a base reference for each version they have.

Nikosokey, it would be very helpful for all of us if you would do a brief write up with your schematic attached (so we can reference this to one of Alex's uploads). If you could explain any changes or problems you faced and how you solved these (briefly) this would be an excellent resource.

Likewise if would be useful if anyone who has built a working revision could do the same and we'll start to have a working structure for all persons 🙂
Click to expand...

Hello matt09 , yes I agree with you about posting both design + schematic. I think that this is what it went wrong in the other thread and ended in a complete mess.

Anyway, could you please help me finish the 2 pair version for those who have the boards ?

Thank you
 
#14
alex mm said:
@obiwankenobi
Sorry but your schematic not so good ...... some errors, need to be corrected .
Why you don't use original schematic?
An externally hosted image should be here but it was not working when we last tested it.
Click to expand...

alex mm thank you for you advice, I don't use the original circuit because so much has been said about errors that I don't trust the source. This is why I opened this thread for. I am trying to complete the amplifier in an orderly way so we can use the 2 pairs of output power MOSFET'S version that match the boards I bought from NagysAudio.

I corrected the errors you signaled, sorry for that. The original schematic (please see post #1) indicates 63 V for this capacitors. Would you like to specify another voltage ? why ?

Post #1 contains all the original circuits. As you will see the protection circuits came in an untidy 2 hand written sheets that I tried to reflect in this new version. I need help to know if this is correct and if somebody has tested this protection as shown.

Thanks
 

Attachments

Last edited:
#16
Hello friends, just to complete the components and materials, here is the source for the original transformer specified by NagysAudio. This is the reply of the email received and the quotation for such a toroidal transformer.

Here is the link to the vendor: Avel Lindberg

Hello Roberto:

Thank you for your kind email and interest in AVEL products. We are pleased to offer:

Type: Y236753
2 pcs: $69.89 ea.
Delivery: Stock
FOB: CT - shipping via USPS Flat Rate to Florida +$11.00, direct to Argentina +$46.00
MasterCard, Visa, Discover accepted.

The primaries are wound for 115+115V, 50/60 Hz and will operate with a 220V, 50 Hz input. You would need to series connect the primaries.

To order, please call 860-355-4711, x 1, or fax 860-354-8597.

We look forward to meeting your transformer needs.

Very best regards,
Melanie Roman
Avel Lindberg Inc.
47 South End Plaza
New Milford, CT 06776
860-355-4711, ext 41
Fax: 860-354-8597
Click to expand...

Of course we can use any other matching transformer, but this is what was recomended. I talked to Melanie some time ago, very nice person, excellent attention.
 
You must log in or register to reply here.
Top Bottom