Attention: OTP
Hey Piero7, i think that i remember you from other thread:
Remote Control Kits of Mr. Mikkel Simonsen.
Fotis
Yes, it was a bad experience
Hum in my FU29 was cause of first and second stage vcc filament supply. Trashed the original single diode used, graetz bridge+new big capacitors, no more hum. Plus, I changed the HT supply (one capacitor was really down, plus changed the HT diodes with fast ones). In my FU29 couple capacitors was two fake Wima. I changed these too.
Hello,
I also have a FU29 amplifier and I'm planning to do some upgrades.
First I used my multimeter to get the schematics. In the attachments you'll find the circuit of one channel and the PS of both channels.
The mods that I'm planning to do are:
- replace input tube 6N3 with 5670 (2C51) (already done, that was easy )
- Add chokes to PS and make separate PS for left and right channel
- augment the current through the input tubes from 2ma to 4ma
- replace pot with ladder attenuator
- replace critical components with better ones, especially the coupling caps
Regards,
Danny
I also have a FU29 amplifier and I'm planning to do some upgrades.
First I used my multimeter to get the schematics. In the attachments you'll find the circuit of one channel and the PS of both channels.
The mods that I'm planning to do are:
- replace input tube 6N3 with 5670 (2C51) (already done, that was easy
)- Add chokes to PS and make separate PS for left and right channel
- augment the current through the input tubes from 2ma to 4ma
- replace pot with ladder attenuator
- replace critical components with better ones, especially the coupling caps
Regards,
Danny
Attachments
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Hello,
I own a modified Revon SE 6L6 mini Amp. (cheap)
Also an Yaqin ML-10 and a YAQIN MS34.
My newest was the Audioromy M-828A, it arrived safely in 2 days from china.
But the sound was a little bit dump.
I changed the LS Control to ALPS 27 Series and add a 7H Chocke in Power Supply.
But the sound was not better. So I ordered pre Amp Tubes for testing.
Then today I received several tubes.
i.e. two USA Penta 5670 from 1973 tubes to exchange the chinese 6N3.
And I exchanged the russian 6n23P to the Phillips 6922 from 1987.
For the Audioromy M-828A this was an great improvement in the soundstage.
Womens Voices will now fly through the room and orchestral music will loose its stiffness.
These two types of tubes are a fantastic match for improvement of the Audioromy M-828A.
Changing the chinese FU29 to the russian GU29 is only a very little step foreward, but changing the 6N23 and 6N3 to Phillips 6922 and Penta 5670WA will change this Amp and take it to another stage in HiFi Ratings.
happy Listening
Dieter
I own a modified Revon SE 6L6 mini Amp. (cheap)
Also an Yaqin ML-10 and a YAQIN MS34.
My newest was the Audioromy M-828A, it arrived safely in 2 days from china.
But the sound was a little bit dump.
I changed the LS Control to ALPS 27 Series and add a 7H Chocke in Power Supply.
But the sound was not better. So I ordered pre Amp Tubes for testing.
Then today I received several tubes.
i.e. two USA Penta 5670 from 1973 tubes to exchange the chinese 6N3.
And I exchanged the russian 6n23P to the Phillips 6922 from 1987.
For the Audioromy M-828A this was an great improvement in the soundstage.
Womens Voices will now fly through the room and orchestral music will loose its stiffness.
These two types of tubes are a fantastic match for improvement of the Audioromy M-828A.
Changing the chinese FU29 to the russian GU29 is only a very little step foreward, but changing the 6N23 and 6N3 to Phillips 6922 and Penta 5670WA will change this Amp and take it to another stage in HiFi Ratings.
happy Listening
Dieter
Hello Dieter,
I also got a 828A early this year and use him with Duetta loudspeaker with approx. 89dB. First action was also to replace the chinese 6N3 and 6N23 with russian NOS. Like you already mentioned I agree fully with you that this was the biggest enhancement in sound quality. To replace the 4 fake WIMA coupling capacitors with Mundorf capacitors was only a small enhancement, like to replace the FU-29 tubes with GU-29 NOS too.
But one question. Compared to the Yaqin ML-10 and MS-34 how you classify the modified FU-29 from sound point of view? Better or more worse? More Bass or less? I know it would be a kind of subjective opinion but it would help me to decide if I order a MC-10. (I need a second Tube amplifier and now in the "choosing" phase, MC-13s, MC-10, MC-20, Ballad Audio SP6MK3 are my favorites actually, Budget approx. 600 Euro).
Greetings,
Joerg.
Comparing Yaqin to Audioromy
For comparing these Amps you need the same Preamp and the same Loudspeakers.
All my Tube Amps are connected to two pairs of Technics SB6000 with 93db and one pair of Technics SB7000 with 95db at 1Watt and 1m.
For Reference I hade a complete chain of Technics Solid State series 9000 with the 9010,9020,9040,9050,9070 and the SLM1 and RS1500 to check the sound.
To my taste the Audioromy is softer than the Yaqin MC10 and the MC10 is softer than the MS34B.
The MS34B is near to HiFi like the Solid State, but sometimes with womens voices, I need this little sidestep from HiFi, which makes these Tube-Amps so delightful.
This impressive little mis-adjustement of the Tube-chain makes the difference from HiFi.
If you use Loudspeakers, which are able to give this to your room and to your ears you will have fun.
Then the music makes fun and will put a smile on your face.
With 90% of the music program I am listening,I think the 2way SB6000 sounded better than the SB7000 3way or the ASW Alpha 4 Way (95db).
This is my impression not my measurement!!! Every measurement is something completely different!!
Happy listening
Dieter
For comparing these Amps you need the same Preamp and the same Loudspeakers.
All my Tube Amps are connected to two pairs of Technics SB6000 with 93db and one pair of Technics SB7000 with 95db at 1Watt and 1m.
For Reference I hade a complete chain of Technics Solid State series 9000 with the 9010,9020,9040,9050,9070 and the SLM1 and RS1500 to check the sound.
To my taste the Audioromy is softer than the Yaqin MC10 and the MC10 is softer than the MS34B.
The MS34B is near to HiFi like the Solid State, but sometimes with womens voices, I need this little sidestep from HiFi, which makes these Tube-Amps so delightful.
This impressive little mis-adjustement of the Tube-chain makes the difference from HiFi.
If you use Loudspeakers, which are able to give this to your room and to your ears you will have fun.
Then the music makes fun and will put a smile on your face.
With 90% of the music program I am listening,I think the 2way SB6000 sounded better than the SB7000 3way or the ASW Alpha 4 Way (95db).
This is my impression not my measurement!!! Every measurement is something completely different!!
Happy listening
Dieter
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This is not a single ended amp... so why would you expect it to sound like one? Either way it is pretty hard to beat it's performance for the money. It easily trounces the Stereo 70.
I have had one of these for about 2 1/2 years now. Mine is the second version that has been sold over the years. Has been totally reliable except the Chinese tubes. I;ve been using NOS RCA outputs with Russian drivers and inputs. I do notice a little bit of hum in it and people with highly efficient speakers also notice this to a larger degree, so starting by modifying the power supplies would make much more sense unless yours has some failed parts in it. I have one here for service right now that has a bias issue so it will be interesting to see what's up with it.
Mark
I have had one of these for about 2 1/2 years now. Mine is the second version that has been sold over the years. Has been totally reliable except the Chinese tubes. I;ve been using NOS RCA outputs with Russian drivers and inputs. I do notice a little bit of hum in it and people with highly efficient speakers also notice this to a larger degree, so starting by modifying the power supplies would make much more sense unless yours has some failed parts in it. I have one here for service right now that has a bias issue so it will be interesting to see what's up with it.
Mark
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i had this amp sent to me for repairs...
the 829b tube on one channel tends to red plate...
so what i did was to convert this amp to cathode resistor bias
by cutting the negative supply line to the grid and
installing cathode resistors and grid leaks to ground...
so now this amp did not require fiddling with bias pots no more...
and as far as sound quality goes, the owner did not detect any difference
in sounds before and after the mods...
this is one such "hot" amp....
the 829b tube on one channel tends to red plate...
so what i did was to convert this amp to cathode resistor bias
by cutting the negative supply line to the grid and
installing cathode resistors and grid leaks to ground...
so now this amp did not require fiddling with bias pots no more...
and as far as sound quality goes, the owner did not detect any difference
in sounds before and after the mods...
this is one such "hot" amp....
Attachments
Mine always worked just fine, although I sold it about six months ago. Be aware there are several,variants all built on the same chassis. The last variant whichnisnthe one I had was very reliable. Some of the earlier variants not so good. The later variant was built on the same PCB as the others with some different parts placement and so on...
Mark
Mark
i would think so...this amp runs hot....
G2 supply can be improved by using a mosfet regulators...
B+ seems high so that filter caps run on the brink...
but otherwise, this is a good sounding amp, i am making my own version
using bigger power traffos and OPT's.....
Attachments
I wish to use my Audioromy FU29 as a power amplifier only, with a separate preamplifier front end. Can I convert to power amp by simply bypassing the volume control? Mine is the later version with four 5670W and I assume two of them act as preamp/buffer? So would it be better to bypass the front-end 5670W when converting to a power amp? TIA
The version I have also with 4 x 5670WA (about a year old now) is a Williamson type design so you can't do what you propose if yours is like mine. Even more the case is that working on the PCB other than simple changes is difficult because the sockets are bolted to the chassis prior to installing the PCB, and soldering the sockets.
I would just pad the input signal for use with an external line stage, and get rid of the volume control.
I would just pad the input signal for use with an external line stage, and get rid of the volume control.
Kev thanks for your reply. Have you had any reliability issues with your amp? I have not received mine yet, but have GE 5670W and RCA 829B tooooobes (US made) in waiting to replace the Chinese versions. I've also read about mods to lower the plate wattage + using grid stoppers to inhibit red-plating/oscillation... but wonder if that's necessary on later version of these amps?
On the input impedance match, assume the aurom FU29 is already impedance matched for aux/CD? I have a Musical Fidelity Preamp 3 with line out impedance about the same around 8K impedance at output.... so... (recall I am a newbie at this) ... all I would have to do is delete the volume control, and I can use the MF3 with the audiorom FU29? thanks again
On the input impedance match, assume the aurom FU29 is already impedance matched for aux/CD? I have a Musical Fidelity Preamp 3 with line out impedance about the same around 8K impedance at output.... so... (recall I am a newbie at this) ... all I would have to do is delete the volume control, and I can use the MF3 with the audiorom FU29? thanks again
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