SYMEF amplifier

The SYMEF amplifier has moved here.
SYMEF Type S
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SYMEF T2 Schematic
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Schematic link for V 2024: https://www.pcbway.com/project/shareproject/SYMEF_Audio_Power_Amplifier_8bb70aa8.html
SYMEF Ensemble https://www.pcbway.com/project/shareproject/SYMEF_Ensemble_audio_power_amplifier_bf5439e4.html


USER FEEDBACK
  1. ... Extreme grip on the woofers....... Yes I almost fainted when i played Lee Ritenour as the first note. .... I felt the bass note right in my guts.....It is natural since this amp plays ridiculously good and I would like to be able to use it with my setup..... Have been playing with the amp some hours now. The initial harshness in the upper regions seems gone. Suspect some burn-in time. Only beautiful music. ......... I have tried alot of amplifiers during my HIFI - time. This is maybe the first transistor amp I have tested that really grips the woofers and are very dynamic at very low volumes.......... Vocals seem 'real' and I have not tried any classical yet................ Symef just keeps impressing me.. I have a hard time saying this but my tube power amp may get early retirement........
  2. First contributor to trying out the SYMEF design. In listening test, surely it has beaten my carver receiver. I have used a behringer mixer with low ,mid and high control and to control the volume of the signal because I did not put a volume control on the amp. I compare the symef to my carver coz it has also high ,mid and low control. symef turned my tower speaker(Yamaha) sounds like a big speaker. Voice of the artist sounds big and the bass is very good even at low volume. I really like the mids and lows of this amp. That's why its sounds very natural to me. thank you so much for this amplifier. I am very satisfied with this amp. It is really worth of my money, time and energy. Now my worries are over the amp. is working and sound is excellent.
  3. I received a positive listening experience with SYMEF in the entire tonal range. But it was particularly the tremble that attracted my greatest attention, and I wanted to investigate this further. On my 'main' equipment I play my CDs from a Sinology NAS to a Aspirator Transporter(with Squeezebox Duet). The rest: A strongly modified DCX 2496 (Janneman) takes care of the crossover and equalizing. The three final amplifiers are: NAD 208 for two subs and two Goldmund Mimesis clones(3 and 9) for the rest of the range. Speakers are Magnepan 1.6 and NHT 1259. This equipment, I feel, is of high quality and have so far met my needs and my perception of what constitutes good HIFI. To get an impression, I did the following: I played a number of discs 'in parallel' (on the same time) from 1).My main equipment, and from 2).My Copland 288 connected to SYMEF. I could switch between these two possibilities(they were synchronized to always be on the same place on the CD), or let them play simultaneously. This way, I could confirm that there really were differences in the reproduction of high frequencies. The next move was the following: I disconnected the Goldmund 3 from my main equipment. Then I connected SYMEF, which I have calibrated so that I would not 'let me fall' for the amplifier that delivers the most powerful output signal to be the 'best'. The differences between SYMEF and Goldmund 3 were confirmed. I have been sitting all night and played through my countless discs: OnAudio congratulations 'We have winner.' I have so far been very pleased with how my main system has played almost every music genres. I say almost, as I have, playing classical music, had a small complaint: I generally have a large, wide and deep sound stage when I play other kinds of music. I do not experience the same degree been present when I play classical music. My Goldmund 3 has also had a touch of 'rawness' in the upper treble that has always annoyed me a bit. Violins and cellos now have more air around them, becomes cleaner. More clarity in the overall sound. My impression is that the entire orchestra 'growing' = being bigger.
  4. Its a very enjoyable amplifier with a lively presentation. The mids are lust, particularly with female voices euphoric that easily seduces. The bass is present with great control and is very well-defined. The highs are rich and detailed (you can hear the little details and articulation of the voices).
  5. This is a very good amplifier! Indeed, the formula works.
  6. Very nice! Everything went up smoothly at power-on, excellent sound stage very similar to my Leach build but with a heavier bass punch. Pretty silent to no turn on and off thump and with all that messy wiring during test, hum problem did not occur I currently amplifier Symef of Pinnocchio. It is connected with a tube preamp Conrad, with the source files loss - less 16 - bit and 24 - bit.The speakers are my design, Tubassons Mark 2(3 ways, 2 x woofer SB17, mid SB12, tweeter SC6620). I listen for at least a few weeks. This is one of the best amp I 've heard. My regular amplifier is a Goldmund Mimesis 29 clones that Pinnochio assembled (MOS FET 5 w Class A, 85 w / c 8 ohms). In comparison, a Symef as transparent or nearly at the top of the spectrum. I am very surprised. But it is in the lower register and the lower mid range that Symef is definitely higher. I listen to jazz, classical, folk and rock.The bass is not only powerful, but it is very precise and articulate. The lower mid range is excellent and allows us to appreciate the voices of men as well as women. Whether it 's a live or studio recording, the music that comes out of this amp is highly musical, and this with minimal coloration. The icing on the cake is the realism of the sound image, as with classical and Jazz very powerful. Whatever the volume, the image is stable and the instruments are very well spaced.The image is 3 d.The sound stage is realistic and very close to a single - ended tube amplifier. This with power and ease way to reproduce very detailed very complex musical messages. I still can not believe it.
  7. There is no hint of any oscillation, bias is quite stable, and vbe multiplier is quite responsive to heat sink temperature. Probably need to adjust the bias after it reached steady state. Measured 1 kHz and 10 kHz square wave and 10 kHz sine wave response, its clean and rounded edges on square waves. Played through my home made bookshelf speakers. In one word, the sound is marvelous. Although I have to do an extensive listening, the amp just displays its character in the first song itself. Sound stage is huge, vocals are accurate and highs are detailed. Overall the sound is very balanced in the whole audio range, no slamming bass or shrill voice. Its just perfect;you don 't want to stop listening. I am not comparing this amp in isolation. I 've already built SymAsym, and F5 also I have coupled Lux man amps, so I have some very good amps for reference. Having said that, this is a very good sounding amp with huge sound stage and openness. I don 't know what your magic formula is, but it is wonderful. I cannot stop listening to this amp.
  8. It cannot be explained with words, it have to be listened to in real life.
  9. Further listening with the amp I, m more and more impressed with the ease in which it can take you into another world. I can, t wait to build the other channel and use better parts, to bring out this best this amp can do.
  10. A lot of great designers in this world that will make us confused. Finally, I decided to assemble this amp. Thank you, Sir for the support. Only with a potluck part, the SYMEF is really different. Yes....this amp is unbelievable. Very easy adapted according to our tastes. Very convenient be heard(of all kinds of music), The bass is more than power full, Very clear articulations, the high is very crisp and smooth. With the MP3 format(196 kbps) even no less with the FLAC. Maybe you won't believe it, but this is the reality. Sorry for my bad English Thank you, Sir, you make my life happier
  11. The sound is very transparent. It brings out the best of recordings specially of female vocals. I compared it to my AV receiver, and I am impressed with the sound. It seems more natural and the music is more alive. With no input signal, there is no hum or hiss with my ears directly on the tweeters! I used a 500w SMPS with additional 20kuF capacitors, and I am very happy with it. The amp is completely silent.
  12. Very nice! Everything went up smoothly at power-on, excellent sound stage very similar to my Leach build but with a heavier bass punch. Pretty silent to no turn on and off thump and with all that messy wiring during test, hum problem did not occur Thank you sir Harrison
 
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The forum software only allows a limited number of file extensions and 'asc' is not one of them. To post the LTspice file, rename it first - change foo.asc to foo.asc.txt or foo.txt before you upload it. Those downloading it does the opposite before using the file.

Alternately, you can zip the file and then post it.
 
:cop:

Notice: Due to a software glitch, this post by AndrewT is being reposted by me.

Post:

R1 & R28 don't work. The Vdrop with Iq=1.15mA is far too low.

C8 seems to interfere with audio quality.

R8 with Iq~100mA seems good, but R7 with Iq~1mA seems wrong.

Which part of this schematic is loosely based on BA-3?
__________________
regards Andrew T.
 
:cop:

Notice: Due to a software glitch, this post by AndrewT is being reposted by me.

Post:

R1 & R28 don't work. The Vdrop with Iq=1.15mA is far too low.

C8 seems to interfere with audio quality.

R8 with Iq~100mA seems good, but R7 with Iq~1mA seems wrong.

Which part of this schematic is loosely based on BA-3?
__________________
regards Andrew T.

Hi Andrew T. did everything work out ?
 
A Jfet and a cascode should be a good thing to add.

And I don't think Hafler or anyone can patent any of this... fortunately.
Thanks Carlmart,

The first part of the amplifier (Before VAS) can operate on lower rails lets say +-15V DC thus the cascode may not be necessary.

However I did not notice any advantage over the current design though I stand to be corrected.

Yes this maybe one flavor.