Leach LowTIM is my favourite amp.
NCC200, GB150, Hitachi MOSFET are also good.
AKSA is good if you want a rose tinted sort of sound - can struggle with complex music and rhythms though.
P3A and NAP140 clones OK but sound a bit rough.
Jim's Audio Mimesis (bipolar version) is fairly good - very clear and tight sounding.
Aleph 30 - Yawn, in fact YAWN!!!!
Chip amps - OK for a few quid I suppose
JLH 80W MOSFET amp - v. good with a different PS.
All IMO.
Currently building a DX Blame ES/ST/TMC
NCC200, GB150, Hitachi MOSFET are also good.
AKSA is good if you want a rose tinted sort of sound - can struggle with complex music and rhythms though.
P3A and NAP140 clones OK but sound a bit rough.
Jim's Audio Mimesis (bipolar version) is fairly good - very clear and tight sounding.
Aleph 30 - Yawn, in fact YAWN!!!!
Chip amps - OK for a few quid I suppose
JLH 80W MOSFET amp - v. good with a different PS.
All IMO.
Currently building a DX Blame ES/ST/TMC
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Good morning. It was had gig yesterday.
Bluegrass!
Welleman should work just fine. I'm not shure about output relays but you can replace them with some schrack/tyco types with more contacts and parallel them to get lower resistance.
About RMI-FC100. It looks really promising. A lot of outputs in parallel which gives you low output z and very nice front end.....IT ROCKS. But. It is probably not suitable to drive 8 ohm speakers at high levels because of somehow low supply voltage? How much power should it deliver? I suspect something over 50W rms at 8 ohm load. Which means that amp falls in to clipping fast if you crank it up. But i like it really, don't get me wrong. I am an sound engineer and i worked in recording studio and on live gigs as well so i maybe expect from amps something else than mostof other people, I don't know....but i hate amp to clip. But there is another thing too. Difference for an example from 50wpc to 100wpc gives only 3dB higher level......on the other hand 20%of clipping can easy destroy tweeters. It is just never ending story.
I must drink my cup of Earl Grey, after that I'll check about those boards in basement where lies my workshop. Today is really sunny and warm here in Ljubljana. Nice.
Best regards to all
Taj
Bluegrass!
Welleman should work just fine. I'm not shure about output relays but you can replace them with some schrack/tyco types with more contacts and parallel them to get lower resistance.
About RMI-FC100. It looks really promising. A lot of outputs in parallel which gives you low output z and very nice front end.....IT ROCKS. But. It is probably not suitable to drive 8 ohm speakers at high levels because of somehow low supply voltage? How much power should it deliver? I suspect something over 50W rms at 8 ohm load. Which means that amp falls in to clipping fast if you crank it up. But i like it really, don't get me wrong. I am an sound engineer and i worked in recording studio and on live gigs as well so i maybe expect from amps something else than mostof other people, I don't know....but i hate amp to clip. But there is another thing too. Difference for an example from 50wpc to 100wpc gives only 3dB higher level......on the other hand 20%of clipping can easy destroy tweeters. It is just never ending story.
I must drink my cup of Earl Grey, after that I'll check about those boards in basement where lies my workshop. Today is really sunny and warm here in Ljubljana. Nice.
Best regards to all
Taj
Hello
Bluegrass, I'm afraid that those Quad clone cards have gone somewhere. I couldn't find them so I made new pair for you. It is nice home brew. I used 70um boards for batter result. About materials for this amp. It is just nothing special. It is good to use 1% metal foil resistors and some good quality foil caps. But there are only 2 caps which could possibly affect to the sound. First is of course input 0,68uF cap and the other is 47nF cap located in the feedback of the op amp. Only somehow special components are 560E 3-4w resistors but you can order from farnell. About op amp. It works with practically every single op amp in dip8 pack. I tried tl071, ne5534, op27...and many others. I prefer opa604, because of it's good price performance ratio. I work with sound every single day and I think that difference between op604 and some expensive op amps, is so minor that is hard to measure and almost impossible to hear because of modest requirements of quad's input stage. My favorite is opa604. And now transistors. For small signal transistors i suggest MPSA 42/92 types if you choose supply voltage higher than +-50V. Drivers are MJE15031 or something similar. In fact there is everything ok if you choose some slower drivers like BD244c. Output transistors which I use are just simple and somehow conservative MJL21194. You can get them cheap but be sure that they are original ON SEMI. NO china fakers. If there is somebody who can help you to match them it will be nice. You can also built your own transistor tester. Measure them by use of universal V,A,Hfe....meter just doesn't make any sense because conditions of measurement are unrealistic for such big transistors......But if is too hard for you to match outputs i can calm you down. These devices are excellent and are made in tight tolerance. There is cc 20% of mismatch.
So nothing special. I'll check downstairs if there is some of small material for these amps....resistors diodes....and will send it to you as well. It is worth almost nothing so don't bother. I'll be glad to spare you some work.
Good night
Bluegrass, I'm afraid that those Quad clone cards have gone somewhere. I couldn't find them so I made new pair for you. It is nice home brew. I used 70um boards for batter result. About materials for this amp. It is just nothing special. It is good to use 1% metal foil resistors and some good quality foil caps. But there are only 2 caps which could possibly affect to the sound. First is of course input 0,68uF cap and the other is 47nF cap located in the feedback of the op amp. Only somehow special components are 560E 3-4w resistors but you can order from farnell. About op amp. It works with practically every single op amp in dip8 pack. I tried tl071, ne5534, op27...and many others. I prefer opa604, because of it's good price performance ratio. I work with sound every single day and I think that difference between op604 and some expensive op amps, is so minor that is hard to measure and almost impossible to hear because of modest requirements of quad's input stage. My favorite is opa604. And now transistors. For small signal transistors i suggest MPSA 42/92 types if you choose supply voltage higher than +-50V. Drivers are MJE15031 or something similar. In fact there is everything ok if you choose some slower drivers like BD244c. Output transistors which I use are just simple and somehow conservative MJL21194. You can get them cheap but be sure that they are original ON SEMI. NO china fakers. If there is somebody who can help you to match them it will be nice. You can also built your own transistor tester. Measure them by use of universal V,A,Hfe....meter just doesn't make any sense because conditions of measurement are unrealistic for such big transistors......But if is too hard for you to match outputs i can calm you down. These devices are excellent and are made in tight tolerance. There is cc 20% of mismatch.
So nothing special. I'll check downstairs if there is some of small material for these amps....resistors diodes....and will send it to you as well. It is worth almost nothing so don't bother. I'll be glad to spare you some work.
Good night
Hi Tajzmaj,
Thanks so much for the effort you are putting in, I really appreciate it. I used the opa604 with my Quad 405-2, it came with the upgrade kit i bought, and seems to work really well. I appreciate your working with sound, in that way we are similar. I practice and record everyday, and play gigs of course. I think doing recording gives you a 'common sense' approach to sound and gear. Things need to sound good, but also be good value for money, and above all, reliable. Expensive cables don't make much sense once you know what cables are used for mics etc. Just good quality standard cables sound great to me! So with these boards, I will need to get some advice from you on how to build the amp and what other bits i should get. This will be my first amp semi-build, and lets face it, you are doing lots of the hard work for me. All the best for now, and thanks!
Thanks so much for the effort you are putting in, I really appreciate it. I used the opa604 with my Quad 405-2, it came with the upgrade kit i bought, and seems to work really well. I appreciate your working with sound, in that way we are similar. I practice and record everyday, and play gigs of course. I think doing recording gives you a 'common sense' approach to sound and gear. Things need to sound good, but also be good value for money, and above all, reliable. Expensive cables don't make much sense once you know what cables are used for mics etc. Just good quality standard cables sound great to me! So with these boards, I will need to get some advice from you on how to build the amp and what other bits i should get. This will be my first amp semi-build, and lets face it, you are doing lots of the hard work for me. All the best for now, and thanks!
Beauty of Mihai's FC-100 is that your loudspeakers will operate to ~90dB continuous in Class A.
And with constant heat dissipation limited to about 40W per channel, due to the modest rail voltages.
The rails may not produce 100W/8 continuous, but close to 200W peak in 6 Ohm is a lot of power, imo.
(btw, you could easily bump it up to a +100W level, if you prefer Watts over Amps)
And with constant heat dissipation limited to about 40W per channel, due to the modest rail voltages.
The rails may not produce 100W/8 continuous, but close to 200W peak in 6 Ohm is a lot of power, imo.
(btw, you could easily bump it up to a +100W level, if you prefer Watts over Amps)
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Uf sorry to fall down for two days. Gigs,gigs.....
Bluegrass, i will draw and write everything to you that it should be easy to build this amp.....Have you got any option to buy proper enclosure in Sweden....Otherwise there is quite good company in Italy.
modushop.biz
Don't expect to much from this enclosures but they deliver fast and for my opinion have fair price performance ratio. You will nee something like 3H and 300mm deep, and with such heat sinks it will run almost cool. Again reliable......
Caps. I put something around 2x20000uF for each channel. It is good idea to buy more smaller caps and wire them parallel to get higher current and less inductance. They should be rated 80V at minimum. 100 volts is maybe batter value if you like to leave your amplification ON for long periods......it will increase life time of caps.
For an example
200pcs Cornell Dubilier 80v 2700uf snap in Capacitors | eBay
This is good price. Of course you don't need them such amount but can use them in some future projects. Otherwise you can try find something from Farnell....
Best wishes and Happy New Year He he
Taj
Bluegrass, i will draw and write everything to you that it should be easy to build this amp.....Have you got any option to buy proper enclosure in Sweden....Otherwise there is quite good company in Italy.
modushop.biz
Don't expect to much from this enclosures but they deliver fast and for my opinion have fair price performance ratio. You will nee something like 3H and 300mm deep, and with such heat sinks it will run almost cool. Again reliable......
Caps. I put something around 2x20000uF for each channel. It is good idea to buy more smaller caps and wire them parallel to get higher current and less inductance. They should be rated 80V at minimum. 100 volts is maybe batter value if you like to leave your amplification ON for long periods......it will increase life time of caps.
For an example
200pcs Cornell Dubilier 80v 2700uf snap in Capacitors | eBay
This is good price. Of course you don't need them such amount but can use them in some future projects. Otherwise you can try find something from Farnell....
Best wishes and Happy New Year He he
Taj
has anyone tried these?
Lm60 - Lateral Mosfet Power Amplifier Kit by AmpsLab
kinda expensive.
any proven, great sounding class AB amps similiar to the one in the link
for diy?
Lm60 - Lateral Mosfet Power Amplifier Kit by AmpsLab
kinda expensive.
any proven, great sounding class AB amps similiar to the one in the link
for diy?
Sorry not by me. I have collection of classical ,,legendary,, amps, properly renewed and the others are my own home brew products. If you are experienced by making pcbs I can post you p-cad file for kind of quad 405 clone. I have nice version for 2x100w output. Small card.....but without any documents and instructions how to build it. I have it just bare. It works. Proven. But you need some skills.You have to watch circuit and make the rest. I also see some really nice projects here on diy Audio.
Nice weather ...mmmmm...warmth....finally.
Nice weather ...mmmmm...warmth....finally.
Just a few more important things about building an good quality amplifier. Maybe it would be batter to start new thread for all the beginners but.......
When you choose right circuit which satisfies your needs such as quality, power, reliability, weight(touring applications),size,price......and many others, I sometimes build something just for fun and because i am curious how it works.........
Very important is than to build amplifier good in mechanical aspect. It should be compact, you should track the logic of the circuit. For an example. It is bad idea to put inputs and power transformer close together unless you want some hum to be present all the tome as a background in your music......
Some elements dissipate heat and it is very bad idea to mount them in contact with electolytic capacitors......
And now the output transistors. They should be mounted on heat sinks large enough or too big for the power which they should cool down. Operational temperature should not exceed some 60 degrees of celsius, or lifetime will be reduced. It is important to mount transistors on absolutely flat surfaces. Be care full on edge around the hole which you drill. Firstly there is no flat surface and secondly it will punch through mica insulator and cause at least short circuit to the power lines if it wont even destroy something. Try to avoid rubber insulators because they are mechanically sensitive and ere hard to remove when are overheated if amp needs some repair. Don't scrimp with thermal conductive paste. Excess of it is good to clean because otherwise the dust will stick on it.......
It is also important to have good ventilation of enclosure, or all of elements especially caps will suffer from reduced lifetime.
Be prepared that when you once complete bare electronic there are costs just began. Mechanic is more than 2/3 of the final cost.
When you choose right circuit which satisfies your needs such as quality, power, reliability, weight(touring applications),size,price......and many others, I sometimes build something just for fun and because i am curious how it works.........
Very important is than to build amplifier good in mechanical aspect. It should be compact, you should track the logic of the circuit. For an example. It is bad idea to put inputs and power transformer close together unless you want some hum to be present all the tome as a background in your music......
Some elements dissipate heat and it is very bad idea to mount them in contact with electolytic capacitors......
And now the output transistors. They should be mounted on heat sinks large enough or too big for the power which they should cool down. Operational temperature should not exceed some 60 degrees of celsius, or lifetime will be reduced. It is important to mount transistors on absolutely flat surfaces. Be care full on edge around the hole which you drill. Firstly there is no flat surface and secondly it will punch through mica insulator and cause at least short circuit to the power lines if it wont even destroy something. Try to avoid rubber insulators because they are mechanically sensitive and ere hard to remove when are overheated if amp needs some repair. Don't scrimp with thermal conductive paste. Excess of it is good to clean because otherwise the dust will stick on it.......
It is also important to have good ventilation of enclosure, or all of elements especially caps will suffer from reduced lifetime.
Be prepared that when you once complete bare electronic there are costs just began. Mechanic is more than 2/3 of the final cost.
Hi Tajzmaj,
This sounds great.I can't wait to try and put it all together. I will order an enclosure from Italy as you suggest, one with heat sinks built in is i think what you recommended. Then i will try and source the other parts maybe after talking to you.. I am interested in Mic pres , especially for powering a ribbon mic which has a very low output. Any advice very welcome. Bluegrass
This sounds great.I can't wait to try and put it all together. I will order an enclosure from Italy as you suggest, one with heat sinks built in is i think what you recommended. Then i will try and source the other parts maybe after talking to you.. I am interested in Mic pres , especially for powering a ribbon mic which has a very low output. Any advice very welcome. Bluegrass
Hey Bluegrass
About the enclosure. This amp fits nice in enclosure 300mm deep and 3H high, with heat sinks on both sides. If I am correct there they have rack version or 10mm front panel version......and also black or ,,blond,, . But check shipping. You know, I'm from Slovenija and Italy is our neighbor so shipping is cheap. I have from my home to the Venice only 250Km.........so check. And don't expect too much. Those enclosures have good price ratio but have some cheap mechanical solutions.
Most mic preamps which I use have some 60dB gain but as you probably noticed has some hiss when you open them too much, like all good sounding preamps. But who cares if the sound is nice. Look at the Neve 1073. It has a lot of hiss.
Best regards
Taj
About the enclosure. This amp fits nice in enclosure 300mm deep and 3H high, with heat sinks on both sides. If I am correct there they have rack version or 10mm front panel version......and also black or ,,blond,, . But check shipping. You know, I'm from Slovenija and Italy is our neighbor so shipping is cheap. I have from my home to the Venice only 250Km.........so check. And don't expect too much. Those enclosures have good price ratio but have some cheap mechanical solutions.
Most mic preamps which I use have some 60dB gain but as you probably noticed has some hiss when you open them too much, like all good sounding preamps. But who cares if the sound is nice. Look at the Neve 1073. It has a lot of hiss.
Best regards
Taj
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