And which amp is that??
Many people think that by improving the theoretical aspects will also improve the perceived sound. But in reality, after the born of so many new improved designs we still use old designs. If your mind is 100% theory, I don't think you will use lateral MOSFET at all...
And if what you had in mind is another BIPOLAR design (hopefully I'm wrong) then I would like to cry. Please point me to a superior design where I can use my Hitachi laterals (and may be I have built them after all). Slew rate above 100V/us, power about 60W
Hi,
I have ID the components on the original schematic post by Nagys using Krisfr's scheme. I tried to us Krisfr's posted schematic but it was blurr when I zoom in. Just in case anyone might find it useful. (at least I do). Still checking if there is any mistake.
Hi Krisfr,
There is a 330ohm between the feedback of the op-amp module and ground in the original schematic posted by Nagys which does not appear in your schematic. Your R12 should go to the signal ground but it hadn't. Is there any way you can posted a clearer schematic (or is it just my ACDSee software that is screwing up?). Tks. I try to use yours but there are some difference so I labelled the original one. Hope you don't mind I am using your scheme.
I have ID the components on the original schematic post by Nagys using Krisfr's scheme. I tried to us Krisfr's posted schematic but it was blurr when I zoom in. Just in case anyone might find it useful. (at least I do). Still checking if there is any mistake.
Hi Krisfr,
There is a 330ohm between the feedback of the op-amp module and ground in the original schematic posted by Nagys which does not appear in your schematic. Your R12 should go to the signal ground but it hadn't. Is there any way you can posted a clearer schematic (or is it just my ACDSee software that is screwing up?). Tks. I try to use yours but there are some difference so I labelled the original one. Hope you don't mind I am using your scheme.
Attachments
Hello
If I understood well many of us we want these amp as close to the orig as possible .
Some questions
The orig use only 2x 10 000 uF capacitor / channel .
Please let me know if I'm wrong...
Now if we go with the 2PC board / channel that would be 6 x 10 000 uF capacitors.
I read before the Goldmund does keep the power supply simple because more capacitance it would slow done the amp??? It can be a mistake that to..
The Minesis 29 use much less capacitance than your Goldmund..
Nagy would you please share your opinion (experience) about the power supp.
Your Goldmund use two 10 000 uF caps , or I'm wrong?
I just want to be clear about these.
I was interested on a different Goldmund couple months a go. But I had no chance to to get all the original parts , I gave up!
People write all kind of thinks about the amp .. One close picture worth more than 1000 sentences.
If we want to build these clone as close as possible in that case I would like to know everything about the power supply to.
I think is more important the PS than the amp case etc.
Also what size VA rated the power transformer??
Can you post a close picture from your amplifier PC board or please send it direct to mathelaszlo2@yahoo.ca.
I'm serious about these amp , if I build it I do not want to ad any extra parts.
Also what size uH the coil on the output?
Do we need a Preamp to drive the amp or the CD payer can drive it with a good potentiometer.
It would be great to know all these before we go further with the project, or we spend a lot on extra money on parts ..
It would be great to see a close picture to see the capacitor types (Philips BC , Elna , Nippon CC etc)
After my experience (more than 20 years) those thinks are very important to!
Also the orig use solid wire to hock up the PC board or strained wire.
It would be great to know all these think before we participate on the GB.
Usually before I plan to build a amp(any) I want to be sure I can finish it. I try to look up the original parts if available. Not sure always "the best capacitor" give the best result.. All the parts I think it was carefully chose by engineers .
They spent hundreds of hours to get the best result .
We can not go over again on all that process!!!
What I want to write not enough to chose only the orig semis ..
For a good start we need a great PC board (and that we will have thanks to Alex).
But personally I would like to know more about the rest to..
Because the high voltage capacitors we not have many option . It would be great to have all these info and each one of us start to look for the original parts . Or someone organise a GB so we can get discount on the parts .
I do not want to buy PC board to keep on the shelf or because it look nice etc..
Also I'm not a big fan to buy parts from Ebay (Hong Kong , China, Philippines etc)
A lot of counterfeit parts on the Ebay..
Greetings
If I understood well many of us we want these amp as close to the orig as possible .
Some questions
The orig use only 2x 10 000 uF capacitor / channel .
Please let me know if I'm wrong...
Now if we go with the 2PC board / channel that would be 6 x 10 000 uF capacitors.
I read before the Goldmund does keep the power supply simple because more capacitance it would slow done the amp??? It can be a mistake that to..
The Minesis 29 use much less capacitance than your Goldmund..
Nagy would you please share your opinion (experience) about the power supp.
Your Goldmund use two 10 000 uF caps , or I'm wrong?
I just want to be clear about these.
I was interested on a different Goldmund couple months a go. But I had no chance to to get all the original parts , I gave up!
People write all kind of thinks about the amp .. One close picture worth more than 1000 sentences.
If we want to build these clone as close as possible in that case I would like to know everything about the power supply to.
I think is more important the PS than the amp case etc.
Also what size VA rated the power transformer??
Can you post a close picture from your amplifier PC board or please send it direct to mathelaszlo2@yahoo.ca.
I'm serious about these amp , if I build it I do not want to ad any extra parts.
Also what size uH the coil on the output?
Do we need a Preamp to drive the amp or the CD payer can drive it with a good potentiometer.
It would be great to know all these before we go further with the project, or we spend a lot on extra money on parts ..
It would be great to see a close picture to see the capacitor types (Philips BC , Elna , Nippon CC etc)
After my experience (more than 20 years) those thinks are very important to!
Also the orig use solid wire to hock up the PC board or strained wire.
It would be great to know all these think before we participate on the GB.
Usually before I plan to build a amp(any) I want to be sure I can finish it. I try to look up the original parts if available. Not sure always "the best capacitor" give the best result.. All the parts I think it was carefully chose by engineers .
They spent hundreds of hours to get the best result .
We can not go over again on all that process!!!
What I want to write not enough to chose only the orig semis ..
For a good start we need a great PC board (and that we will have thanks to Alex).
But personally I would like to know more about the rest to..
Because the high voltage capacitors we not have many option . It would be great to have all these info and each one of us start to look for the original parts . Or someone organise a GB so we can get discount on the parts .
I do not want to buy PC board to keep on the shelf or because it look nice etc..
Also I'm not a big fan to buy parts from Ebay (Hong Kong , China, Philippines etc)
A lot of counterfeit parts on the Ebay..
Greetings
And which amp is that??
Many people think that by improving the theoretical aspects will also improve the perceived sound. But in reality, after the born of so many new improved designs we still use old designs. If your mind is 100% theory, I don't think you will use lateral MOSFET at all...
And if what you had in mind is another BIPOLAR design (hopefully I'm wrong) then I would like to cry. Please point me to a superior design where I can use my Hitachi laterals (and may be I have built them after all). Slew rate above 100V/us, power about 60W
'Goldmund' is HITACHI HMA-7500 from 1978 with 'improvements', my F100 (with HITACHI MOSFETs) also, you can use old HITACHI design
Attachments
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I have absolutely no problem with ANYONE using the schematic I posted. I will update it tomorrow and hopefully post a totally completed one by the afternoon. I had a steep learning curve for the KiCad and my eyes are not as they once where.
I will re-post with a sharper image, I reduced it too much in order to comply with the DIYAUDIO upload limits. Will do better.
If anyone sees any other errors I will fix and post...
Could someone PLEASE address the issue of the use of a ground plane on the "ORIGINAL" pcbs
Thanks
I will re-post with a sharper image, I reduced it too much in order to comply with the DIYAUDIO upload limits. Will do better.
If anyone sees any other errors I will fix and post...
Could someone PLEASE address the issue of the use of a ground plane on the "ORIGINAL" pcbs
Thanks
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Hi
These is a another Goldmund design. I would be interested on these to .
All I know these is the mono block , newer version.
Any opinion on these schematic??
Unfortunately these PC board to complex to me ....
Some picture and the schematic..
Greets
Gabor
Hey !
These're my puctures that I cloned from original Goldmund for a long time.
I also have a Cloned & modified chassis from JOB to fit with my Goldmund Cloned, he he
Now I used Toroidal transformer instead of EI.
Thanks
Anadigit
Attachments
And which amp is that??
Many people think that by improving the theoretical aspects will also improve the perceived sound. But in reality, after the born of so many new improved designs we still use old designs. If your mind is 100% theory, I don't think you will use lateral MOSFET at all...
And if what you had in mind is another BIPOLAR design (hopefully I'm wrong) then I would like to cry. Please point me to a superior design where I can use my Hitachi laterals (and may be I have built them after all). Slew rate above 100V/us, power about 60W
Just about any bipolar design can be ported to laterals , just drop the Vbe , modify the driver stage and change the basestoppers. My CX (supersym) and GX (luxman) would be VERY happy driving laterals. Guaranteed to blow this circuit out of the water in both the quality and reliability aspects as well. Oh, BTW , both are close to 100v/us ... if that ever really mattered in the perceived sound quality..
To compare MPSA42/92's with 1381/3503 devices is a "no brainer" . OS
Hello Anadigit
Welcome here!
Yes that yours , I posted only so people know the modern Goldmund got simpler than the older ones .
Of course that is not mean the new one sound worst . Actually I never heard not even one!!!!
I don't think a company remain in business if they start produce worst projects. And cost more and more the new project..
Sorry I didn't purchased your kit (only reason I do not like SM resistors)
I would be still interested in case I could chose my favorite resistors.
I hope you don't mind I posted your pictures.
Some people didn't believe that your schematic orig Goldmund!
Greetings
Aren't these JFET's ?
Hello
Yes they are JFet . But when I tested 20-25PC and al dead ...
I thought may be the company put wrong label on the pars so I tested with hfE to.
Nothing , garbage!
Greetings
gaborbela - Please take a look at my schematic on page one. It seems people keep asking the same questions and they are right there on page one. The amp uses (2) 4700uF capacitors per channel. Alex made them into 10,000uF when he designed the PCB, it makes virtually no difference. You can use whatever you like. I wouldn't use below 4700uF personally.
All wire is stranded.
Transformers seem to be 200VA, or so. I cannot see them because they're potted. But again, makes virtually no difference. Use 300VA if you'd like. Or whatever fits into the chassis that you'll be using.
Power supply is extremely simple. (2) transformers per channel, 200VA-300VA, and a standard diode bridge. Thats it!!!!
The rest of the power supply is already in the schematic that I posted on page one and in Alex's PCB.
You will need a preamp to drive this amp, just like you would with virtually every other amp.
Goldmund uses all Philips/BC capacitors.
All Vishay resistors.
Mostly Motorola transistors.
Can someone please explain to me what the "Ground Plane" terminology means? I'm not sure I understand what the problem is, but I would love to hear everyone's thoughts regarding this supposed issue.
All wire is stranded.
Transformers seem to be 200VA, or so. I cannot see them because they're potted. But again, makes virtually no difference. Use 300VA if you'd like. Or whatever fits into the chassis that you'll be using.
Power supply is extremely simple. (2) transformers per channel, 200VA-300VA, and a standard diode bridge. Thats it!!!!
The rest of the power supply is already in the schematic that I posted on page one and in Alex's PCB.
You will need a preamp to drive this amp, just like you would with virtually every other amp.
Goldmund uses all Philips/BC capacitors.
All Vishay resistors.
Mostly Motorola transistors.
Can someone please explain to me what the "Ground Plane" terminology means? I'm not sure I understand what the problem is, but I would love to hear everyone's thoughts regarding this supposed issue.
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I don't have enough money for laterals...
I was planning to do a lateral and/or vertical board. What I don't understand here is the excitement about a old hitachi design that has been refined beyond this long ago. I was building amps tonight , could of built this one in a heartbeat. OS
One thing I see that you do not often see with poweramps is the front end is fed from a regulated supply. I'm not sure why 60VAC is specified when it is then fed through a doubler. I have a feeling this is a mistake. If a higher AC voltage is available than that used to create the main power supply, the doubler arrangement is not needed.
I know that..
My point is that you can take any already great sounding BJT voltage stage like luxman's hawksford cascode or your Goldmund , drive Laterals with it and it will sound all that much better.Your goldmund circuit pushes those old high Cob mpsa92/42 VAS devices to their fastest slew rate by undercompensating them. A modern voltage stage with fairchild devices (like all of mine) do not need to be "pushed to the edge" like this to achieve fast performance.
We all know that the perceived sound of a amplifier is subjective at best but those laterals are made JUST for audio. My old Hitachi lateral amp had a 4 transistor circuit similar to the goldmund running at 20ma HOT class A ,it was the ONLY amp besides the mighty 8000$ genesis stealth (200w class A)that sounded "magical" to me. I was listening to that "hot" class A voltage stage moderated by the Hitachi lateral class AB stage with it's unique switching distortion (BTW , different then that of your typical BJT). APEX audio builds lots of amps , you should listen to him ... that Japanese Lateral amp with the non-switching circuit would be what I would shoot for in a new amp creation , I feel it would easily put the overpriced Goldmund to shame .. BIGTIME.
OS
'Goldmund' is HITACHI HMA-7500 from 1978 with 'improvements', my F100 (with HITACHI MOSFETs) also, you can use old HITACHI design
I happen to own a HMA-7500 and it has indeed a particular good sound with incredible punch and dynamics.
I would strongly advice to start a new thread, giving both opponents and proponents more room for productivity, each with their own valuable approach.
/Hugo
'Goldmund' is HITACHI HMA-7500 from 1978 with 'improvements', my F100 (with HITACHI MOSFETs) also, you can use old HITACHI design
To get some improvements, they just looked at the revised
version , 7500mk2 from 1980....
http://www.diyaudio.com/forums/soli...plifier-i-have-ever-heard-30.html#post2326305
Oh yeah , I also have a voltage tripler similar to the goldmund that runs off of a small 24-0-24 trafo , the only difference is that it feeds a high gain capacitance multiplier before feeding the 20mA rails of the modular voltage stage, WAY superior to the goldmund. Separate grounds , adjustable current sources , all those things a mega thousand dollar amp (should) have .
You should listen to me and apex ,we are "hands on" .. instead of debating abstract opinions , we hear all these amps , see them fail , see which ones stand the test of time , and build a LOT of them (below). maybe I should pot whole voltage stages ... he he..
OS
