There should be no noise when you first turn it on as it takes time for the tubes to warm up. My guess is that your hearing something shorting when you turn it on. If you just brought it,email the seller. was it from hong kong or canada?.How much technical knowledge do you have.It may be best to take it to a repair shop and see if the seller will cover the cost of repairs.I would not turn it in in this condition!
salas said:
I finally got my set of Gold Lion KT88 as well as a set of Tungsol 12AX7 Gold Pins - installed them, adjusted the bias voltage and it sounds so different - all of a sudden, I can hear so much more detail.... Thanks again for your advice. I will save up now for a set of 6SN7, which ones would you go for? Cheers, Spencer
Yakin, no sound
When you connect your CD player at the back, the switch at the front must be set at .25. If you use a preamp it must be set at .6.
The tinny sound is because the selector switch on the left was not at the correct position. Check to see that you did connect the Cd to the Cd input, then select Cd at the front.
The Yaqin 100 is an amazing amplifier which will embarass any inadequate speakers orhCd players.
After purchasing mine, I took it to a high end stereo store, and the salesmen there were shocked at its performance. Now the darn thing is making me purchase a pair of Canton 507 speakers, and I am loking at a McIntosh Cd player.
Hope I helped. Enjoy.
When you connect your CD player at the back, the switch at the front must be set at .25. If you use a preamp it must be set at .6.
The tinny sound is because the selector switch on the left was not at the correct position. Check to see that you did connect the Cd to the Cd input, then select Cd at the front.
The Yaqin 100 is an amazing amplifier which will embarass any inadequate speakers orhCd players.
After purchasing mine, I took it to a high end stereo store, and the salesmen there were shocked at its performance. Now the darn thing is making me purchase a pair of Canton 507 speakers, and I am loking at a McIntosh Cd player.
Hope I helped. Enjoy.
Re: Yaqin MC-100B circuit diagram
hi, Halx:
Can you kindly send the orignal jpeg to my email account?
It's leepc777@hotmail.com
I just bought mc-100b and I would like to see what is the plate votage using for kt88.
thanks,
-Patrick
halx00 said:
hi, Halx:
Can you kindly send the orignal jpeg to my email account?
It's leepc777@hotmail.com
I just bought mc-100b and I would like to see what is the plate votage using for kt88.
thanks,
-Patrick
Hi everyone. Sorry for hijacking thread.
I also have just received a Yaoin 100B and very happy. However when I first setup the thing, I couldn't hear any sounds and when I foolishly switched the input voltage (0.6V/0.25V) switch without turning the amp off, I heard a loud pop from the speakers (like short circuit).
What I am worried is not the amp but rather my comparatively expensive dynaudio speakers. Could someone more experieced with amps and speakers tell me what potential damage I have caused to my speakers. thanks very much!
I also have just received a Yaoin 100B and very happy. However when I first setup the thing, I couldn't hear any sounds and when I foolishly switched the input voltage (0.6V/0.25V) switch without turning the amp off, I heard a loud pop from the speakers (like short circuit).
What I am worried is not the amp but rather my comparatively expensive dynaudio speakers. Could someone more experieced with amps and speakers tell me what potential damage I have caused to my speakers. thanks very much!
It depends on the amplitude and more importantly, the time duration of the pulse plus the peak power handling of your speakers. This is why it is important to have plenty of power reserve on your speakers so they can handle such transients without damage. For example, my speakers are run at around 15 Watts per channel as any more rattles the furniture and brings the neighbours but the speakers are rated 250 Watts peak handling. Long period transients might cook the voice coils but I find that nearly all speakers will handle the problem you had without any damage. I have looked at the circuit of the amp but I would not suspect that switching the gain of the stage in the way it is done would produce such loud pops. I rather fancy at this stage that you may have some DC voltage on the input connectors, along with your AC signal. There are no coupling capacitors in the Yaqin input stage and therefore DC is to be avoided as much as possible. I get similar pops when I connect the sound card of my PC to my Yaqin MC-10L but it is such a tiny amount of DC that the pop is very low in amplitude. Try switching the 600mV/250mV switch with the volume turned down. If the pop is not evident then the source is perhaps DC from either the CD inputs or something on the other inputs. If the pop however is still there, then it must be due to the cathode switching.
You don't really want to briefly turn OFF then back ON the amplifier as it produces very harmful surges to the power supply and output stages. If you do need to turn off, allow plenty of time for the valves to cool before switching back on as this will allow the -70V grid bias supply to get established prior to the output valves pulling current. Hope this helps, Les
You don't really want to briefly turn OFF then back ON the amplifier as it produces very harmful surges to the power supply and output stages. If you do need to turn off, allow plenty of time for the valves to cool before switching back on as this will allow the -70V grid bias supply to get established prior to the output valves pulling current. Hope this helps, Les
I have looked at the circuit of the amp
Hi-Q,
Can you help me, please.?
Is there a way to insert on MC-100B circuit a output subwoofer plug? 🙂
Thanks.
Hi-Q,
Can you help me, please.?
Is there a way to insert on MC-100B circuit a output subwoofer plug? 🙂
Thanks.
I would suggest that the best option is to fit an active sub woofer supplied with audio from the speaker terminals. The downside to this is the active sub woofer levels may need to be adjusted if the output from the main amp is varied. Perhaps a sub woofer with a remote control would be the ideal. Wherever you try to connect internally to the Yaqin you will have this problem unless you wire the sub directly from the signal input that appears at the top of each volume control. The effect of added cabling and lower impedance may however degrade the sound from the main amp. Perhaps someone on the Forum has already found a neat solution to your problem and make a posting on here for you.
Les
Les
Hi Hi-Q,
My speakers are rated at 150W. the amp was on triode mode so max output is about 30W (is this right?). The volume wasn't high, about 9 o'clock.
I have my Yamaha cd and ipod via dock connected at back. nothing at front.
The pop was same loudness as the playing volume at about 10 o'clock. My speaker's sensitivity is only 86dB.
I'm a bit scared to try to switch again given that it can potentially damage my speakers.
By the way, the amp sounds really good but piano is a bit sharp.
Thanks again.
My speakers are rated at 150W. the amp was on triode mode so max output is about 30W (is this right?). The volume wasn't high, about 9 o'clock.
I have my Yamaha cd and ipod via dock connected at back. nothing at front.
The pop was same loudness as the playing volume at about 10 o'clock. My speaker's sensitivity is only 86dB.
I'm a bit scared to try to switch again given that it can potentially damage my speakers.
By the way, the amp sounds really good but piano is a bit sharp.
Thanks again.
OK I have something to add
Howdy gang!!
I hope this helpos a little.]
I have now had this Yaquin MC100B for almost 2 years.
I had not swapped any inetrnal components yet though very temped to do that.
I am using mine fed form the front input direcly form a preamplifier, the mighty Audible Illusions (L-2 heavily modified by Wheezer, wizzard and tweaker extraordinaire), from there PSC Litz silver cables (IC) into Yaq.
Yaqin sound best with either Tungsram ECC-83 circa 1970's or better 1960's still less bright, more detail.
or plain old RCA 5751 Command vblack plates, (fantastic!!) or better yet Sylvania 5751 gray plates, very good bass loads of detail, top end not as lively as Tungsrams.
The for choice of 6SN7's teh best ones so far are Gray glass 1940's or 50's RCA 6SN7's though Ken Rad black plates come in second place along with Russian 6H8C 1950's (only the old Russian are up to par and maybe better toned than the american NOS valves.
I ahve them righht now mixes 2 6SN7 GT Gray Glass and 2 6H8C 1958. it seems to like the best this way for my system speakers and room variables.
Then power tubes:
KT88-98 are pretty decent with good bass and lively top end, Sophia Electric own brew (form Shuguang) of GEK-KT-88 are better more detailed and better mids.
I amm also using (right now playing) NOS 6550 goodl old american Tung-Sol circa late 1960's gray plates with 3 round holes. I have not heard the GE's 6550's in this amp system but I hear they are pretty good too.
I finally settled for this combination:
12AX7 = ECC83 Tungram
6SN7 - 2 RCA Gray Glass 6SN7GT on the outsies (V1 -V4) and Russian 6H8C 1958 black bakelite base bought form Kiev (E-bay) on the inside positions (V2- V3).
all Tung-Sol 6550 power quad.
Voltage reduced form 124 Local grid to 105 via Variac transformer with 11 Amp Capacity.
Bias for the power tubes was adjusted at 725 mA measured form the test points (+- 0.05 mA) adjust the Bias only after the amp had been powered up for more than 40 minutes or so to fully stabilize and reached operating temperature.
Since the input PS voltage is only 105 V / AC, we cna push the power tubes a little harder and make the amp sing much better.
Initially I have fried teh original set of KT-88 Shuguangs that same with the amp due to high voltage.
this amps are designed to receive up to 110 Volts to putput 450 Volts to the tube plates, si if you feed 124 volts you probably get over 550 Volts to the plates and that my friend fries your tubes in a few weeks, also you cna fry an egg n top of the amplifier to boot.
I have arrived to teh conclussion that the perfect voltage for this amp After scoping, testing and measuring distortion and output watts etc. at Wheezer's Super Lab tat the best voltage for this thing should be not more than 105 Volts so I settled in 104 for good measure.
Amp sounds fluid, great mids and crystal top end.
I need to point out that here is a great deal of difference between the sound on triode adn Ultralinear.
Probably the triode sound is a lot better, more dynamic, more delicate, a lot more detail and air around instruments.
UL sound more Rock and roll, more bass not necessarily better,
Mids details are gone and so is air on the uppermost highs.
We also measured A LOT!!! more limited frequency response on UL mode so . . . Triode is the winner.
If you can't hear the difference, you need new speakers, this amp can do details and juicy voices like very few amps I have heard before.
Tones can be just a tube swap away, lots of fun.
highly recommended fro jazz, fusion, classical, percussion, classic rock, even some metal stuff (my Rush CD collection became a lot more listenable), Led Zeppeling took new life, Diana Krall and other moved into my spare room (no, not really but you get the picture it sounds that good).
Harmonic textures, timbres and liquidity took an organic quality that is very difficult to achieve (if not impossible ) with SS gear.
I am not talking a receiver here for comaprison on hand are, modified Sunfire Cinema Grand, Threshold S5000e, Aragon 4004 mK-II, other amplification include Dk Design Reference MK-II (now LS), Hand made SS monoblocks made in Europe 120 WPC sporting 16 power transistors per channel, Granite face plate, very nice presentation very accurate sound. any and all of them very nice in their own class but lacking in organic feel and timbre luster compared to good tubes.
Enjoy your music. Long live tubes!!!
Peace!
G.
Howdy gang!!
I hope this helpos a little.]
I have now had this Yaquin MC100B for almost 2 years.
I had not swapped any inetrnal components yet though very temped to do that.
I am using mine fed form the front input direcly form a preamplifier, the mighty Audible Illusions (L-2 heavily modified by Wheezer, wizzard and tweaker extraordinaire), from there PSC Litz silver cables (IC) into Yaq.
Yaqin sound best with either Tungsram ECC-83 circa 1970's or better 1960's still less bright, more detail.
or plain old RCA 5751 Command vblack plates, (fantastic!!) or better yet Sylvania 5751 gray plates, very good bass loads of detail, top end not as lively as Tungsrams.
The for choice of 6SN7's teh best ones so far are Gray glass 1940's or 50's RCA 6SN7's though Ken Rad black plates come in second place along with Russian 6H8C 1950's (only the old Russian are up to par and maybe better toned than the american NOS valves.
I ahve them righht now mixes 2 6SN7 GT Gray Glass and 2 6H8C 1958. it seems to like the best this way for my system speakers and room variables.
Then power tubes:
KT88-98 are pretty decent with good bass and lively top end, Sophia Electric own brew (form Shuguang) of GEK-KT-88 are better more detailed and better mids.
I amm also using (right now playing) NOS 6550 goodl old american Tung-Sol circa late 1960's gray plates with 3 round holes. I have not heard the GE's 6550's in this amp system but I hear they are pretty good too.
I finally settled for this combination:
12AX7 = ECC83 Tungram
6SN7 - 2 RCA Gray Glass 6SN7GT on the outsies (V1 -V4) and Russian 6H8C 1958 black bakelite base bought form Kiev (E-bay) on the inside positions (V2- V3).
all Tung-Sol 6550 power quad.
Voltage reduced form 124 Local grid to 105 via Variac transformer with 11 Amp Capacity.
Bias for the power tubes was adjusted at 725 mA measured form the test points (+- 0.05 mA) adjust the Bias only after the amp had been powered up for more than 40 minutes or so to fully stabilize and reached operating temperature.
Since the input PS voltage is only 105 V / AC, we cna push the power tubes a little harder and make the amp sing much better.
Initially I have fried teh original set of KT-88 Shuguangs that same with the amp due to high voltage.
this amps are designed to receive up to 110 Volts to putput 450 Volts to the tube plates, si if you feed 124 volts you probably get over 550 Volts to the plates and that my friend fries your tubes in a few weeks, also you cna fry an egg n top of the amplifier to boot.
I have arrived to teh conclussion that the perfect voltage for this amp After scoping, testing and measuring distortion and output watts etc. at Wheezer's Super Lab tat the best voltage for this thing should be not more than 105 Volts so I settled in 104 for good measure.
Amp sounds fluid, great mids and crystal top end.
I need to point out that here is a great deal of difference between the sound on triode adn Ultralinear.
Probably the triode sound is a lot better, more dynamic, more delicate, a lot more detail and air around instruments.
UL sound more Rock and roll, more bass not necessarily better,
Mids details are gone and so is air on the uppermost highs.
We also measured A LOT!!! more limited frequency response on UL mode so . . . Triode is the winner.
If you can't hear the difference, you need new speakers, this amp can do details and juicy voices like very few amps I have heard before.
Tones can be just a tube swap away, lots of fun.
highly recommended fro jazz, fusion, classical, percussion, classic rock, even some metal stuff (my Rush CD collection became a lot more listenable), Led Zeppeling took new life, Diana Krall and other moved into my spare room (no, not really but you get the picture it sounds that good).
Harmonic textures, timbres and liquidity took an organic quality that is very difficult to achieve (if not impossible ) with SS gear.
I am not talking a receiver here for comaprison on hand are, modified Sunfire Cinema Grand, Threshold S5000e, Aragon 4004 mK-II, other amplification include Dk Design Reference MK-II (now LS), Hand made SS monoblocks made in Europe 120 WPC sporting 16 power transistors per channel, Granite face plate, very nice presentation very accurate sound. any and all of them very nice in their own class but lacking in organic feel and timbre luster compared to good tubes.
Enjoy your music. Long live tubes!!!
Peace!
G.
Forgot to coment
Sorry guys forgot tocomment on something . . it si true that you can go crazy and spend on tubes almost as much as you invested in the amplifier but boy!!!! it is worth the extra sweetness, detail and harmonious details, also to start right out of the box with the horrible tubes it still sounds pretty good.
And my friend for the $$ is simply unheard of . . .
Buy one bur in it in with the CHinese tubes, buy a Variac or a buck trnasformer make sure you can feed down to 104 to 105 volts AC power (US) and swap some tubes, even the russian tubes reissues and other like Sovteks and EH sound better than the low signal tubes Chinese.
The output power Tubes Shuguang are OK but .. much to gain form using NOS, and so much fun to roll and evaluate.
Good luck;
G
Sorry guys forgot tocomment on something . . it si true that you can go crazy and spend on tubes almost as much as you invested in the amplifier but boy!!!! it is worth the extra sweetness, detail and harmonious details, also to start right out of the box with the horrible tubes it still sounds pretty good.
And my friend for the $$ is simply unheard of . . .
Buy one bur in it in with the CHinese tubes, buy a Variac or a buck trnasformer make sure you can feed down to 104 to 105 volts AC power (US) and swap some tubes, even the russian tubes reissues and other like Sovteks and EH sound better than the low signal tubes Chinese.
The output power Tubes Shuguang are OK but .. much to gain form using NOS, and so much fun to roll and evaluate.
Good luck;
G
Gonzalo, excellent posts on subject. I sent you a PM but I am not sure you got it at all. So, I am posting here its basic contents. A couple of questions. You calculated the plate voltage values for 110 and 124 mains voltage. What is the plate voltage you would estimate for the 104 volts AC you are using? Do you happen to know the math behind the conversion/calculation of mains voltage to plate voltage? Also, what is the math relationship between plate voltage and recommended power tube bias, or is it a chart publised for the KT88 design standard? My amp (bought from supplier in Canada, I am in NY) is in principle rated for 115 mains AC voltage with recommended bias at 600 mA, but many users in this forum/thread advise against it....they say too high, thus shortening power tube life. They favor something slightly above 500 mA. So, at first glance--not knowing the math involved and the net effect on plate voltage, as well as the bias setting head-room resulting from the reduction to 104 volts AC--it seems to me that, perhaps, the 725 mA that you recommend may be a bit on the high side for the sake of tube life. Your words of wisdom will be very much appreciated.
munosmario
munosmario