incorrect bias for yaqin mc10k
thankyou for answering my question drboyd you replied that the bias was incorrectly set at the factory could you tell me what resistor value you used to correct this problem? do you think i need to change any other components to get this thing stable? thanks, your help would be sincerely appreciated.
thankyou for answering my question drboyd you replied that the bias was incorrectly set at the factory could you tell me what resistor value you used to correct this problem? do you think i need to change any other components to get this thing stable? thanks, your help would be sincerely appreciated.
Be very careful with this amp. I will recommend you bias it correctly using cheap speakers. I have seen some Yaquin amps being self-immolating over a few weeks, especially the model using the 6080 tube at the output. I guess you bought it from CattylinkAnyway, you can always modify it, that's the beauty of tube amps.
Get in touch with Snowy ( he or she never says his/her gender)at
www.cattylink.com , they are the ones who OEM that amp and you must demand full support.
Hope this helps
www.cattylink.com , they are the ones who OEM that amp and you must demand full support.
Hope this helps
modifying yaqin mc10k
thankyou for the replies, when i purchased the amp i intended to modify it with the help of my good friend who was a broadcast engineer from way back, unfortunately he passed away recently and his knowledge and friendship is sorely missed. kooltubes , what do you think the best path for modding this amp would be? i want to put in higher quality output trannys, and better components, what path would you take. I will find out about the bias so i can stop it self immolating and muck around with it as time permits............... WE will find out with any luck drboyd thanks any ideas would be most appreciated
thankyou for the replies, when i purchased the amp i intended to modify it with the help of my good friend who was a broadcast engineer from way back, unfortunately he passed away recently and his knowledge and friendship is sorely missed. kooltubes , what do you think the best path for modding this amp would be? i want to put in higher quality output trannys, and better components, what path would you take. I will find out about the bias so i can stop it self immolating and muck around with it as time permits............... WE will find out with any luck drboyd
thanks any ideas would be most appreciatedbias adjustment
well underneath this amp there are a series of holes through the chassis underneath each bank of valves .When i inspected the holes i found 2 trimpots 1 for each valve, near each trim pot there were adjacent holes , you could see the track on the board and appeared to have a dimple on the end about the size of a test probe.this configuration is repeated on the other channel, my question is would this be the place to adjust with a meter? The trimmers have hex heads so they would be easy enough to adjust.What would be the best procedure when doing the rebiasing ? by the way drboyd i couldnt find that diy forum could you direct me to it? (excuse my ignorance), well with a little help we might get this thing running properly any suggestions would be sincerely appreciated.
well underneath this amp there are a series of holes through the chassis underneath each bank of valves .When i inspected the holes i found 2 trimpots 1 for each valve, near each trim pot there were adjacent holes , you could see the track on the board and appeared to have a dimple on the end about the size of a test probe.this configuration is repeated on the other channel, my question is would this be the place to adjust with a meter? The trimmers have hex heads so they would be easy enough to adjust.What would be the best procedure when doing the rebiasing ? by the way drboyd i couldnt find that diy forum could you direct me to it? (excuse my ignorance), well with a little help we might get this thing running properly any suggestions would be sincerely appreciated.
Here's the link about the guy who fixed his Yaqin MC-10K...
http://www.stereo411.com/forum/view...ht=yaqin&sid=ceb10ec855c109b745838707c9d8e4c7
http://www.stereo411.com/forum/view...ht=yaqin&sid=ceb10ec855c109b745838707c9d8e4c7
link to fix yaqin
hi everyone thats having trouble with this amp.I have a link to ofthis italian guy who has a great handle on how to bias this beast. http://www.audiocostruzioni.com/a_d/idee/biasing-yaqin-c10/biasing-yaqin-c-10.htm best of luck
hi everyone thats having trouble with this amp.I have a link to ofthis italian guy who has a great handle on how to bias this beast. http://www.audiocostruzioni.com/a_d/idee/biasing-yaqin-c10/biasing-yaqin-c-10.htm best of luck
Ouch, i've bought today on ebay the Yaquin MC-10L
That's probably allmost the same amplifier but with EL34 tubes and 6N1 at the frontstage, saying that this amp give you 50w class A what i don't believe. Buyed it from Richtonaudio. Anyone know it? Well i must pay the amp and get it, but want prepared if there is something that i must know before using this amp?
Kind regards
Good buy or bad one?Bought it today for 340 GBP including insurance and transport.
That's probably allmost the same amplifier but with EL34 tubes and 6N1 at the frontstage, saying that this amp give you 50w class A what i don't believe. Buyed it from Richtonaudio. Anyone know it? Well i must pay the amp and get it, but want prepared if there is something that i must know before using this amp?
Kind regards
Good buy or bad one?Bought it today for 340 GBP including insurance and transport.
check the price at http://www.cattylink.com/ 340GBP seems a bit high even with the transport and insurance.
I suggest that you contact them to confirm that your amplifier is an export model which is for 115V-230V operation not the stock chinese model which is 110V-220V. Do not trust what is written on the chassis because they usually mark them as 115V-230V even is the transformer is not wound for Europe.
Hope it's not too late.
I suggest that you contact them to confirm that your amplifier is an export model which is for 115V-230V operation not the stock chinese model which is 110V-220V. Do not trust what is written on the chassis because they usually mark them as 115V-230V even is the transformer is not wound for Europe.
Hope it's not too late.
So they ripped me off a little bit? The amp itself cost 155GBP,all the rest is insurance and package cost. And what can i do in case if it's a model for the chinese market? Complain to Ebay? Please help me because i feeling allready ripped-off and did'nt payed anything untill now.
Kind regards.
Maybe also not so smart,but i've won from another company, named Jennychan4028 buyed a Mr'Liung 845 amp model 2006,wich is a 845 DHT, power supply is marked as 240/110?
Seems that i've bought two mistakes? But when i searched from the net, i saw the 2002 version from this 845 amp available in New-Zealand as a build-kit who was cost more than i've payed for the 2006 version...
Pff help me
Kind regards.
Maybe also not so smart,but i've won from another company, named Jennychan4028 buyed a Mr'Liung 845 amp model 2006,wich is a 845 DHT, power supply is marked as 240/110?
Seems that i've bought two mistakes? But when i searched from the net, i saw the 2002 version from this 845 amp available in New-Zealand as a build-kit who was cost more than i've payed for the 2006 version...
Pff help me
I bought the China made tube gears from ebay in the past.
Some good, some not so good, the lesson, like others have already said - don't trust what they describe literally. If I am going to buy any gears from that origin, I will:
1. Search around to see there is any comment to similar product
(remember, many are just a rebadge of another brand).
2. Add the cost up (price + shipping + XXX) where XXX is the custom
to pay (e.g. when ship to US, the shippng company pays the custom, and in turn, charge handling fee onthe top, I paid as high as 25% of the purchase price!!!)
This price has to be comparable to similar product that I can buy in US and at least 25% lower.
No need to worry, not worth the grief. You may have a jewel, it is not that they are all broken. It is just that they ain't built the same qulaity.
Good luck!!
Some good, some not so good, the lesson, like others have already said - don't trust what they describe literally. If I am going to buy any gears from that origin, I will:
1. Search around to see there is any comment to similar product
(remember, many are just a rebadge of another brand).
2. Add the cost up (price + shipping + XXX) where XXX is the custom
to pay (e.g. when ship to US, the shippng company pays the custom, and in turn, charge handling fee onthe top, I paid as high as 25% of the purchase price!!!)
This price has to be comparable to similar product that I can buy in US and at least 25% lower.
No need to worry, not worth the grief. You may have a jewel, it is not that they are all broken. It is just that they ain't built the same qulaity.
Good luck!!
I just saw,that for the Yaoquin that they're voltage is 110-220v so it's a misstake? what can i do,complain with ebay or else? I don't want to have an amplifier who is goin to have a failiure,because i live in Belgium,and the voltage is here 230V,so 10v more, and also indirect heated tubes have a margain... what must i do?
The difference between 220V and 230V is less than 5% and not all that likely to cause a problem. I would be surprised if there was any actual difference at all in the power transformer for a 115/230 labelled version and the 110/220 versions.
Properly designed electronics should work over at least a +/- 10% range from nominal line of 230V and if CE approved this will certainly be the case. (May not be CE approved in which case the import of such items into the EU is not strictly legal.)
I think you might find it difficult to cancel the bid under these circumstances. eBay makes few allowances for buyer's remorse. Lack of CE approval might be a legitimate way to cancel the auction but I'm not sure about that.
I'd get the amplifier and see where you stand. Simple mods to deal with these sorts of issues are less significant than some of the comments I've seen about tube matching and bias issues in these amplifiers.
Properly designed electronics should work over at least a +/- 10% range from nominal line of 230V and if CE approved this will certainly be the case. (May not be CE approved in which case the import of such items into the EU is not strictly legal.)
I think you might find it difficult to cancel the bid under these circumstances. eBay makes few allowances for buyer's remorse. Lack of CE approval might be a legitimate way to cancel the auction but I'm not sure about that.
I'd get the amplifier and see where you stand. Simple mods to deal with these sorts of issues are less significant than some of the comments I've seen about tube matching and bias issues in these amplifiers.
Thanx, i've send ebay anyway a mail and the seller also, but the original manufacturer say that the europe models are (for CE) more safe than for the china market. At the other hands,i'll prefer an amplifier for the same price who is properly designed with CE . Had i know,another seller offer this same amp with CE and 230V,looks exactly the same,but inside can be a difference!
Kind regards, and i'l let you know how it goes
Kind regards, and i'l let you know how it goes
In UK the AC voltage is officially 230V but it reaches 245V during the day and 240V in the evening. I have bought similar amps in the past and was obliged to change the power transformer; it is not so much the primary which is the problem, it is the secondary
As far that I know, Yaquin is not CE approved and their products are not RoHS compliant; it is a known fact that many manufacturers from the Far-east are not CE approved but their products are always marked CE.
You can get in touch with your seller and ask him to change the transformer at the factory: it is normally done without any surcharge.
The only way out is to ask your seller if the gears are RoHS compliant, if they are not, your goods may be seized by the customs; if the amps are RoHS compliant, the seller must email/fax you the certificate and include a copy with the shipping documents. RoHS became law in Europe since July 2006. http://www.rohs.gov.uk/
The seller that I can recommend is cattylink; they sell the export models; units are tested prior shipping and they accept returns in case of faults; average shipping cost is about 90 GBP or less.
Don't forget that you may have to pay customs duties...after all where is the bargain?
As far that I know, Yaquin is not CE approved and their products are not RoHS compliant; it is a known fact that many manufacturers from the Far-east are not CE approved but their products are always marked CE.
You can get in touch with your seller and ask him to change the transformer at the factory: it is normally done without any surcharge.
The only way out is to ask your seller if the gears are RoHS compliant, if they are not, your goods may be seized by the customs; if the amps are RoHS compliant, the seller must email/fax you the certificate and include a copy with the shipping documents. RoHS became law in Europe since July 2006. http://www.rohs.gov.uk/
The seller that I can recommend is cattylink; they sell the export models; units are tested prior shipping and they accept returns in case of faults; average shipping cost is about 90 GBP or less.
Don't forget that you may have to pay customs duties...after all where is the bargain?
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