Thanks for all the posts. I made a few amateur observations which are as follows.
The Pass F4/5 seems to be very well respected all round but more expensive to build. (class A i think?)
A good quality chip amp is cheaper to build but still high up sound wise with the right components, using Im3886 as an example.
Panasonaudio also recommended for their amp kits.
Another aspect is of course my lack of experience and electronics knowledge, which may mean i need a kit rather than to build from scratch.
Right now two builds seem appealing.
1:Find a Pass f5 kit if one exists
2:Find a really high quality chip amp kit ......
Do these seem fair observations?
Am i on the right lines? Thanks
The Pass F4/5 seems to be very well respected all round but more expensive to build. (class A i think?)
A good quality chip amp is cheaper to build but still high up sound wise with the right components, using Im3886 as an example.
Panasonaudio also recommended for their amp kits.
Another aspect is of course my lack of experience and electronics knowledge, which may mean i need a kit rather than to build from scratch.
Right now two builds seem appealing.
1:Find a Pass f5 kit if one exists
2:Find a really high quality chip amp kit ......
Do these seem fair observations?
Am i on the right lines? Thanks
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The one bigun recommended... Roenders rmi-FC100 , or my AX with it's TMC. Both amps have near PPM distortion. Good ol' invisible 
. I hear the differences in different high end sound cards or CD vs. FLAC vs. MP3 , not the amp.
Also , pay just as much attention to the power supply and output stage , if not more .... that is what you are really hearing (or not hearing ).
OS
. I hear the differences in different high end sound cards or CD vs. FLAC vs. MP3 , not the amp.Also , pay just as much attention to the power supply and output stage , if not more .... that is what you are really hearing (or not hearing
).OS
The one bigun recommended... Roenders rmi-FC100 , or my AX with it's TMC. Both amps have near PPM distortion. Good ol' invisible
Also , pay just as much attention to the power supply and output stage , if not more .... that is what you are really hearing (or not hearing
OS
Excellent advice but somewhat cryptic for the uninitiated
You really need to read and search the forum particularly
for the superbly thoughtout designs from previous years.
e.g The ROENDER design
http://www.diyaudio.com/forums/solid-state/111756-rmi-fc100-single-stage-audio-power-amplifier.html
'RMI-FC100, a single stage audio power amplifier
This is my latest amplifier design. For me, the quest of finding the best sounding amplifier is over.
Firs of all, I want to thanks to MikeB and JCarr, they was my source of inspiration and to Mr. Nelson Pass for a key advice regarding folded cascode topology.
This amplifier has borne as a freeware project and it is dedicated to this marvelous community of enthusiast people that adhere to share knowledge and experience.
I'll start with few pictures. Tomorrow I will continue with specs, amplifier schematics and front end regulated PSU.
Attached Thumbnails
RMI-FC100, a single stage audio power amplifier-1.jpg'
Yours Sincerely
John
PS
Mr Ovidiu-Syn08 site is a good read
Home
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Or this site (where he "hangs out") ... DIY Audio Engineering - Index
Finally able to digest 90+ % of the content , just started reading it. It seems I have independantly come to some of the same conclusions concerning linear amplification .. it is good to be right.
Some new members are timid and won't just jump into a fully discrete amp project. This is the best way to learn about even IC amps. Most STK amp modules are basic LIN topology , the 3886 is just another flavor of this (below - LIN w/widlar CM + quasi OPS
). It is EASY to exceed IC amps with discrete.And , if you mess up , you can fix them (can't fix a chip
).OS
Attachments
PCB's are available from the diyAudio store - link at the top of the page.
F5 kits are available from Tech DIY Company Store
I would say that in case you would like SS amp it does not make any sense to compete with modern FABs while trying assemble and tune discreet topology. Moreover well regarded in most DIY schematics discreet parts like some TOSHIBA JFETs you will discover almost impossible to buy nowadays. But you can get the perfect JFET input stage buying modern opamps from AD, LME or TI very easily in contra. Actually US FABs like Texas Instruments outperforms the rest of the world so hunting some rear outdated parts or looking for substitutions while trying matching pairs just a waist of time IMHO.
Go with LM3886 to get some experience first, it would provide sufficient power and current to drive some conventional not special hi eff speakers. Add some decent opamp as an input stage with some hi quality capacitors and invest further efforts into decent speakers build.
In case class A discreet design looks appealing go with tubes. Triod Electronics good place to start with tube power amp kit they do have eBay store that ships worldwide.
Unless you have the big buck 40's, going supreme exotic with Harbeths isn't sound minded.
At 85-86 dB efficiency, big heat PL clones that handle the load would almost be larger than the loudspeaker.
On the other hand, i seriously doubt that chippy amps with BBC monitor afterlifes would truly make you happy.
Harbeth monitors and Mihai's power amp undoubtedly make a good combo, the RMI-FC100 is one H of a DIY design.
Then, you say your experience with amp building amounts to diddly squat.
Means you'd have to start with a chip amp anyway.
Hello Bluegrass
If you're happy with the sound of the QUAD then a similar BUT improved
design might be what you're looking for.
The GEMM by Graham Maynard is a very well documented and
thought out design.
The GEM
http://www.diyaudio.com/forums/soli...repare-your-ears.html?perpage=10&pagenumber=1
Have a good read of his site_it should be well within a beginner's
capabilities:
Here is a quote from his site
During the 1970s the Quad Hi-Fi company patented their '405' Current Dumping design. It remains as powerful, good sounding, compact and reliable as it was then, and so remains a decent second-hand buy. I used one myself and marvelled at their theoretical ingenuity, though for me the 2x KT88 Leak TL50+ still provided better dynamic reproduction. Since then the Current Dumping circuit has been repeatedly refined for professional or home use, and yet whilst updated models remain available today, so too does a more recently released Quad 2x KT88 II-40 monoblock chassis, and for 2007 - a 4x KT88 Quad II-Eighty !!!!! That Current Dumping circuit cleverly combines both class-B and class-A output stages via a reactive output bridge which allows for the slower class-B switching. With my own circuit however, I have combined both class-AB and class-A outputs in real time, this to provide powerful audio reserves with a class-A like cleanliness, whilst retaining the kind of transparency at higher output powers more often associated with expensive push-pull triodes or the ultralinear kinkless tetrode (KT) designs. (Prior to this my favourite/reference power amplifier had been my own 1975 homemade hybrid 100Wmax 4x KT88 UL push-pull AB1, with SS differential input/phase splitter feeding a pair of ECC82s, each one running as a gain stage plus cathode follower per push-pull half.).
I also believe the performance of the GEM is future proof and will not be superceded by digital amplifier designs, because dynamically energised loudspeaker system back-EMFs cannot fail to interact at higher audio frequencies with the integral filters necessary to prevent digitally switching output stages from becoming RF noise transmitters. Class-A//D is a possibility, but that would seem to be a contradiction in terms of both complexity and modal efficiencies.
Yours Sincerely
John
PS
Hope this information is of help.
Try and find download Mr. John Curl's collected thoughts on what he considers
important design considerations in his designs_this should be available on the Internet as a pdf.
It's an excellent guide on what you should be thinking of implementing.
If you're happy with the sound of the QUAD then a similar BUT improved
design might be what you're looking for.
The GEMM by Graham Maynard is a very well documented and
thought out design.
The GEM
http://www.diyaudio.com/forums/soli...repare-your-ears.html?perpage=10&pagenumber=1
Have a good read of his site_it should be well within a beginner's
capabilities:
Here is a quote from his site
During the 1970s the Quad Hi-Fi company patented their '405' Current Dumping design. It remains as powerful, good sounding, compact and reliable as it was then, and so remains a decent second-hand buy. I used one myself and marvelled at their theoretical ingenuity, though for me the 2x KT88 Leak TL50+ still provided better dynamic reproduction. Since then the Current Dumping circuit has been repeatedly refined for professional or home use, and yet whilst updated models remain available today, so too does a more recently released Quad 2x KT88 II-40 monoblock chassis, and for 2007 - a 4x KT88 Quad II-Eighty !!!!! That Current Dumping circuit cleverly combines both class-B and class-A output stages via a reactive output bridge which allows for the slower class-B switching. With my own circuit however, I have combined both class-AB and class-A outputs in real time, this to provide powerful audio reserves with a class-A like cleanliness, whilst retaining the kind of transparency at higher output powers more often associated with expensive push-pull triodes or the ultralinear kinkless tetrode (KT) designs. (Prior to this my favourite/reference power amplifier had been my own 1975 homemade hybrid 100Wmax 4x KT88 UL push-pull AB1, with SS differential input/phase splitter feeding a pair of ECC82s, each one running as a gain stage plus cathode follower per push-pull half.).
I also believe the performance of the GEM is future proof and will not be superceded by digital amplifier designs, because dynamically energised loudspeaker system back-EMFs cannot fail to interact at higher audio frequencies with the integral filters necessary to prevent digitally switching output stages from becoming RF noise transmitters. Class-A//D is a possibility, but that would seem to be a contradiction in terms of both complexity and modal efficiencies.
Yours Sincerely
John
PS
Hope this information is of help.
Try and find download Mr. John Curl's collected thoughts on what he considers
important design considerations in his designs_this should be available on the Internet as a pdf.
It's an excellent guide on what you should be thinking of implementing.
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Many thanks for all the suggestions, i can see i am in for a lot of reading and thoughtful reflection. Of course its one thing to thing about which amp would suit, another to consider my ability/inability to build it. The ideal solution would of course be to hear some of these amps, ultimately i do trust my ears, and feel fairly confident i would know which suited me once i heard them. If any Swedish contributers living near Stockholm have built any of these amps, let me know, i would love to hear them.
Hi to all
Bluegrass!
I have 303 and 405 as well. For me 303 is kind of muddy and 405 become aggressive when played loud plus it runs too hot with loads under 8e. Chip based amps are good for first project but (my opinion) cant compare with discrete ss competitors. Class A amps are hard to build due you have to match huge amounts of outputs if want to get decent power. If you like quads you can buy quad 606,707,909 and renew it(transistors,caps....) Those amps sounds somehow more ,,polite,, than analytic 405.
Or if you want to build something powerful with huge headroom for domestic or studio use, i can give you a pair of pcbs which are kind of 405 on steroids and use 3 pairs of power transistors per channel and need cc+-60 volts of supply. This amp works 100% without any adjustment. And you can build it cheap. Let me know if you want to play with it because i must dig pcbs from my workshop.I will send cards to you for free.
Best regards
Taj
Best regards
Bluegrass!
I have 303 and 405 as well. For me 303 is kind of muddy and 405 become aggressive when played loud plus it runs too hot with loads under 8e. Chip based amps are good for first project but (my opinion) cant compare with discrete ss competitors. Class A amps are hard to build due you have to match huge amounts of outputs if want to get decent power. If you like quads you can buy quad 606,707,909 and renew it(transistors,caps....) Those amps sounds somehow more ,,polite,, than analytic 405.
Or if you want to build something powerful with huge headroom for domestic or studio use, i can give you a pair of pcbs which are kind of 405 on steroids and use 3 pairs of power transistors per channel and need cc+-60 volts of supply. This amp works 100% without any adjustment. And you can build it cheap. Let me know if you want to play with it because i must dig pcbs from my workshop.I will send cards to you for free.
Best regards
Taj
Best regards
Uf what a day.....Bluegrass I'happy to see your interest. So here come some more details about amp. I hate to describe sound like ,,mm like cream and butter,, or something similar. I use it to power my AR10pi which are lazy. It plays good even when i listen something orchestral like Philip Glass. Cello sounds great.......blah blah blah.....
It is also possible to build lighter version. You just reduce psu voltage. I dont know how much power do you need.
Be careful because with amp like this is very easy to burn out your precious speakers.
And be aware in such amp are present LETHAL VOLAGES. There is cc120VDC rail to rail and supported by huge transformer and big batery of caps.....
It is also absolute must to build DC protection for speakers too. I can help you with it also.
Be good
Taj
It is also possible to build lighter version. You just reduce psu voltage. I dont know how much power do you need.
Be careful because with amp like this is very easy to burn out your precious speakers.
And be aware in such amp are present LETHAL VOLAGES. There is cc120VDC rail to rail and supported by huge transformer and big batery of caps.....
It is also absolute must to build DC protection for speakers too. I can help you with it also.
Be good
Taj
Borrow a BIG, HEAVY 100+ watt solid state amplifier from a friend and determine if it makes any difference in sound.
From the website, most Harbeth speakers are low efficiency (85db/watt) and spec’ed for 50W min. Harbeth recommends a 200W amp! A 100W like your Quad 405 seems a good target, which is above Gainclone capability. Most Quad 405 magazine reviews give it a marginal grade. I have not heard Harbeth’s, but the website discusses the extensive engineering put into their wide bandwidth 8” midrange. This might be the reason your violin ear enjoys their sound.
"Forbidden Planet" is the 1959 Sci-Fi movie which introduced us to Robbie the Robot and an advanced race called the Krell. The Krell had developed technology that provided POWER...UNLIMITED POWER... that could be used to fulfill their dreams. Naturally, even the Krell still had a primitive subconscious mind which immediately used this power to destroy their entire civilization. Same story can be told for power amplifiers and home life.
The best sounding amplifiers I have purchased or built had VER LARGE power supplies. A fully regulated power supply for the front end. A capacitor-inductor-capacitor CLC filtered output power supply. Once you bring home 50 pounds of transformers, inductors and capacitors a psychological change will convert your subconscious into Krell, and only a discrete component power amp with 6-8 Thermatrak bipolar output transistors will fulfill your dreams.
RMI-FC100 or RMI-FC100 MKII would be a good choice to DIY.
From the website, most Harbeth speakers are low efficiency (85db/watt) and spec’ed for 50W min. Harbeth recommends a 200W amp! A 100W like your Quad 405 seems a good target, which is above Gainclone capability. Most Quad 405 magazine reviews give it a marginal grade. I have not heard Harbeth’s, but the website discusses the extensive engineering put into their wide bandwidth 8” midrange. This might be the reason your violin ear enjoys their sound.
"Forbidden Planet" is the 1959 Sci-Fi movie which introduced us to Robbie the Robot and an advanced race called the Krell. The Krell had developed technology that provided POWER...UNLIMITED POWER... that could be used to fulfill their dreams. Naturally, even the Krell still had a primitive subconscious mind which immediately used this power to destroy their entire civilization. Same story can be told for power amplifiers and home life.
The best sounding amplifiers I have purchased or built had VER LARGE power supplies. A fully regulated power supply for the front end. A capacitor-inductor-capacitor CLC filtered output power supply. Once you bring home 50 pounds of transformers, inductors and capacitors a psychological change will convert your subconscious into Krell, and only a discrete component power amp with 6-8 Thermatrak bipolar output transistors will fulfill your dreams.
RMI-FC100 or RMI-FC100 MKII would be a good choice to DIY.
Linesource, that sounds frightening, but i would love to hear it! Your right about the Harbeth's, and I can tell you they sound absolutely fantastic, all i ever need. The RMI-FC100 or RMI-FC100 MKII was recommended earlier and could well be a future project if i survive the build of this 405 type clone. Remember, i have very little electronics experience.
Tajzmaj, yes I guessed i would need to build the amp around the cards, get a case etc. I will leave my very dependable 405-2 well alone. In terms of dc protection, I already have a Velleman K4700 kit which i was thinking of using in my 405-2, but ended up keeping the origional circuit. Do you think that will fit the bill ? In terms of the rest of the build , any tips or documents relating to the build, best parts etc would be very much appreciated!
Tajzmaj, yes I guessed i would need to build the amp around the cards, get a case etc. I will leave my very dependable 405-2 well alone. In terms of dc protection, I already have a Velleman K4700 kit which i was thinking of using in my 405-2, but ended up keeping the origional circuit. Do you think that will fit the bill ? In terms of the rest of the build , any tips or documents relating to the build, best parts etc would be very much appreciated!
Follow this link - DIY Audio Articles From Elliott Sound Products
There you get answer(s) to ALL your question(s) about sound quality and sonic difference between different amplifiers designs including Valves, BJTs and FETs AND many more that you didn't even think about. Zero bias pure information guaranteed.
PS- most guys here don't like him for he offers too much truth, so much that it can harm your current "beliefs" and disturb your love and respect to certain popular amplifiers and certain popular guys. So, check it at your own risk.
Anyone who sees through the myths of expensive cables is worth a read! Thanks for the link.
Follow this link - DIY Audio Articles From Elliott Sound Products
There you get answer(s) to ALL your question(s) about sound quality and sonic difference between different amplifiers designs including Valves, BJTs and FETs AND many more that you didn't even think about. Zero bias pure information guaranteed.
PS- most guys here don't like him for he offers too much truth, so much that it can harm your current "beliefs" and disturb your love and respect to certain popular amplifiers and certain popular guys. So, check it at your own risk.
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