Yes its reg frond end and replace the hot Voltage doubler
Temporariy no.
Soon we will present new board of Golmund clone 9.2
Member
Joined 2009
Paid Member
Bigun
for saying the right thing only someone who has made different amplifiers can tell how it sounds and this amp.
My opinion is that this is a very good amplifier.
I agree the sound of this amp is very good. Light, soft and detail, a bit little of bass...
I have a bit experience, after when i've tried many style of same topo, i have some advice:
- Currents mirror of VAS must be balanced of currents. This will get the best result. Matching devices is important. Hfe is good enough.
- Try run VAS's currents as low, no more 6mA per side. High current will get the sounding tighter. Goldmund Telos run at 3.8mA per side. If you can, you need improve the VAS diff pair, to removing Early effect, more linear by a cascode. I've chosen Hawsford cascode.
I have a bit experience, after when i've tried many style of same topo, i have some advice:
- Currents mirror of VAS must be balanced of currents. This will get the best result. Matching devices is important. Hfe is good enough.
- Try run VAS's currents as low, no more 6mA per side. High current will get the sounding tighter. Goldmund Telos run at 3.8mA per side. If you can, you need improve the VAS diff pair, to removing Early effect, more linear by a cascode. I've chosen Hawsford cascode.
Walkalone
I followed your advice. I reduce the current to voltage amplification stage at 5.85mA (before = 6.68mA) i increase the R16=180 the temp reduce at 58 C on Vas . more soft sound more detail
I reinsert the transistors BSS71-74 are more than detail to KSA3503E and KSA1381E.
Anyway thank you for your advice.
I followed your advice. I reduce the current to voltage amplification stage at 5.85mA (before = 6.68mA) i increase the R16=180 the temp reduce at 58 C on Vas . more soft sound more detail
I reinsert the transistors BSS71-74 are more than detail to KSA3503E and KSA1381E.
Anyway thank you for your advice.
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Last edited:
KINDLY RISING A POINT OF ORDER
Hello everybody, I've been absent since last year, after I posted a version of the complete circuit of this project to be approved by you all. Still intact, my two boards that I bought from @NagysAudio and 90% of the components and materials in a box.
I would like to respectfully suggest a point of order, meaning that we can issue a complete schematic of the device including:
@NagysAudio sent me an envelope containing two PCB's and several sheets containing a circuit schematic. To be honest, and besides any previous issues between this member and the thread (not with me particularly), I think that the information received was insufficient, inaccurate and can't tell if really reliable in full.
In the other hand, I can see the thread itself made many addendums and changes to the original approach, so many of them that I don't feel confident in assembling the kit. I could be missing something and I don't like black clouds and fire.
I have read that there are some members like me that have some similar problem or think that there is some chaos and lack of info.
In my case it can be directly caused by my own ignorance, but having assembled other audio kits following the usual rules and had not much trouble. I know that there are real audio experts out there but I am just a hobbyist, with a degree in electronics, not just a newbie.
Here is my suggestion:
By means of everybody's collaboration, we could offer our experience in an orderly manner, in this way.
Then:
Divide those who could make this project work with original boards and those who had cut traces, add modules, reworked grounding, etc. Lets orderly hear opinions
Finally:
Hear those who had use the original PCB's and made changes for good concerning currents, voltages, component values, but always in the case they could make it work fine, not just valuable theory.
As a final point, there are many concerns about power supply, transformer data, and specially about the protection circuit and power up for the first time.
Please, tell me what you think about this initiative. I think it could be done very easily. But the important think is to ask those who could get the project work.
I have tried to contact members that had made beautiful new boards, but had no reply. Others used a superior version of the original circuit, which is not the one proposed by @NagysAudio who provided PCB's to people like me.
I would be more than happy to cooperate to get a complete original version and also to post a single experimental version with some good changes.
@NagysAudio has been very kind to me by the time I bough the goods from him, as I asked for some details many times to his email and he always responded and also gave me a list of alternatives and suppliers with contact names for special hard to find parts. He insisted many times that the circuit was the original and that there was no need to make any changes to it. I gave him my credit because I don't have any reason to doubt at this. But the many changes and opinions are very confusing, so I decided not just to complain, but to offer some of my time to help order this project documentation.
Please forgive me if I'm late but I believe that I can find members to help this be done. I live in Buenos Aires, Argentina and you could probably can't figure out what it costs to buy and ship parts via FedEx to my country, specially from different sources. I would like to put hands on this project and listen to what I think is a very nice amplifier design.
Best wishes for you all, guys !
Roberto
Hello everybody, I've been absent since last year, after I posted a version of the complete circuit of this project to be approved by you all. Still intact, my two boards that I bought from @NagysAudio and 90% of the components and materials in a box.
I would like to respectfully suggest a point of order, meaning that we can issue a complete schematic of the device including:
- original general amplifier circuit
- original power supply
- original protection circuit
@NagysAudio sent me an envelope containing two PCB's and several sheets containing a circuit schematic. To be honest, and besides any previous issues between this member and the thread (not with me particularly), I think that the information received was insufficient, inaccurate and can't tell if really reliable in full.
In the other hand, I can see the thread itself made many addendums and changes to the original approach, so many of them that I don't feel confident in assembling the kit. I could be missing something and I don't like black clouds and fire.
I have read that there are some members like me that have some similar problem or think that there is some chaos and lack of info.
In my case it can be directly caused by my own ignorance, but having assembled other audio kits following the usual rules and had not much trouble. I know that there are real audio experts out there but I am just a hobbyist, with a degree in electronics, not just a newbie.
Here is my suggestion:
By means of everybody's collaboration, we could offer our experience in an orderly manner, in this way.
- Compose a team of members that would like to order this project
- Declare how many of you own the original PCB's
- Declare who has really finished assembly and if the boards are running
- Read my version of the original @NagysAudio 's schematics
- Help compare if this new version is correct or not, why ...
- Do changes and fixes until accurate against real running projects
- Discuss about components and materials possible equivalences
- Arrive to a final list with working equivalences
Then:
Divide those who could make this project work with original boards and those who had cut traces, add modules, reworked grounding, etc. Lets orderly hear opinions
Finally:
Hear those who had use the original PCB's and made changes for good concerning currents, voltages, component values, but always in the case they could make it work fine, not just valuable theory.
As a final point, there are many concerns about power supply, transformer data, and specially about the protection circuit and power up for the first time.
Please, tell me what you think about this initiative. I think it could be done very easily. But the important think is to ask those who could get the project work.
I have tried to contact members that had made beautiful new boards, but had no reply. Others used a superior version of the original circuit, which is not the one proposed by @NagysAudio who provided PCB's to people like me.
I would be more than happy to cooperate to get a complete original version and also to post a single experimental version with some good changes.
@NagysAudio has been very kind to me by the time I bough the goods from him, as I asked for some details many times to his email and he always responded and also gave me a list of alternatives and suppliers with contact names for special hard to find parts. He insisted many times that the circuit was the original and that there was no need to make any changes to it. I gave him my credit because I don't have any reason to doubt at this. But the many changes and opinions are very confusing, so I decided not just to complain, but to offer some of my time to help order this project documentation.
Please forgive me if I'm late but I believe that I can find members to help this be done. I live in Buenos Aires, Argentina and you could probably can't figure out what it costs to buy and ship parts via FedEx to my country, specially from different sources. I would like to put hands on this project and listen to what I think is a very nice amplifier design.
Best wishes for you all, guys !
Roberto
Hello dear alex mm and Machina. First of all, I would like to thank alex mm for his patience and excellent artworks during the thread. Please friends, could you tell me if this board you designed worked fine with the original circuit, please ? I am so confused that I don't like to assemble the board until I receive some feedback from somebody confirming this. I have a pair of the TO3 version from Nagysaudio that I bought along with a box full of specified components. I am confused about this board working fine also ... I would have to finish reading more that 1000 posts from the complete thread. Could you please tell me if this worked OK ? I contributed a complete circuit schematic by that time but nobody answers my question 
Thank you
Roberto
Thank you
Roberto
Hi. I'm planning to buy TO3 version of the ECF10N20 and ECF10P20 Mosfet from Profusion Distributor in Europe. These MOSFET are for the Goldmund clone amplifier, see the huge thread: http://www.diyaudio.com/forums/solid-state/174468-very-best-amplifier-i-have-ever-heard.html
I want to buy 10 of each for me. Next break price are 20, then 100
Prices are: U$8.42/10, 7.55/20, 6.62/100 + shipping (about 40U$, I asked)
See Profusion webpage at: http://www.profusionplc.com/pro/gex/pcatdtl0
I'm planning to buy within 1-2 month. I'll see if there is any interest. I'm located in Canada, so an North America GB would make more sense.
Check the GB if interested: http://www.diyaudio.com/forums/group-buys/256783-gb-exicon-to3-ecf10n20-ecf10p20.html#post3938754
I want to buy 10 of each for me. Next break price are 20, then 100
Prices are: U$8.42/10, 7.55/20, 6.62/100 + shipping (about 40U$, I asked)
See Profusion webpage at: http://www.profusionplc.com/pro/gex/pcatdtl0
I'm planning to buy within 1-2 month. I'll see if there is any interest. I'm located in Canada, so an North America GB would make more sense.
Check the GB if interested: http://www.diyaudio.com/forums/group-buys/256783-gb-exicon-to3-ecf10n20-ecf10p20.html#post3938754
You must reduce R10 until the voltage rise up 81-83Volt or the voltage on resistors
3KΩ R5-R7=3000-3060 mv
