Yaqin VK-2100 tube integrated amp

[Gogas]

Yaqin VK-2100 Wrong Voltage Transformer

Hi all,

I recently purchased a VK-2100 on ebay after reading many of the review here. I was all excited as I powered it up only to be extremely disappointed within seconds.

The silly fools that sold it to me, after confirming I required a 240V version sent me a 110V version instead. I didn't even think to check, silly me, before I plugged it in and it went bang with all the blue flash and smoke. It was only plugged in for about 2 seconds and was disconnected immediately. Total only 3 or 4 seconds powered on.

I was in contact with the supplier Hi_Audio on ebay and they were going to send a replacement. After some time (months now) I realised they had not sent a replacement and are no longer responding to any emails or attempted contact now it looks as if I'm stuck with this one. Beware buyers !!!

MY QUESTION(s): Do you think it is only the transformer that has fried and can I simply replace the 110V transformer with a 240V transformer. Would any other parts have been fried? Would I need to replace any other parts in doing this 110 - 240 conversion? Does anyone know where I can get the appropriate part(s) or even better someone who would be able to complete the work for me? Either way any thoughts would be greatly appreciated.

I am in Melbourne Australia.

I look forward to any input on this matter.

Cheers

GG

 

[youngie]

ok mate i have been on the yaqin vk2100 all day trying to set my bias but all of them are saying diffrent reading some say -12 and some are sayin 31. i am trying to get them all to 25mv for a class a amp. are they meant to be -or +is there a specail way of doing it. kind regards mr young oh and it is a uk amp 230 volt

On that resistor, it would be negative. The idea is that one part of the output stage is constantly pushing out a little current (a + reading across the resistor), while the other part is pulling a little current ( a - reading across the resistor). I normally would have added a ± to the voltages, but I apparently made that edit on my Windows system.

 

[s-petersen]

Hi all,

I recently purchased a VK-2100 on ebay after reading many of the review here. I was all excited as I powered it up only to be extremely disappointed within seconds.

The silly fools that sold it to me, after confirming I required a 240V version sent me a 110V version instead. I didn't even think to check, silly me, before I plugged it in and it went bang with all the blue flash and smoke. It was only plugged in for about 2 seconds and was disconnected immediately. Total only 3 or 4 seconds powered on.

I was in contact with the supplier Hi_Audio on ebay and they were going to send a replacement. After some time (months now) I realised they had not sent a replacement and are no longer responding to any emails or attempted contact now it looks as if I'm stuck with this one. Beware buyers !!!

MY QUESTION(s): Do you think it is only the transformer that has fried and can I simply replace the 110V transformer with a 240V transformer. Would any other parts have been fried? Would I need to replace any other parts in doing this 110 - 240 conversion? Does anyone know where I can get the appropriate part(s) or even better someone who would be able to complete the work for me? Either way any thoughts would be greatly appreciated.

I am in Melbourne Australia.

I look forward to any input on this matter.

Cheers

GG

Unfortunately,everything inthe circuit received twice the voltage,transistors,tube filiments,filter caps are the first possible victims,besides the power transformer.
Best to start a new thread,with pics and a schematic

Nevermind,oldy moldy post from the past

 

[KKnight]

I'd like to revive this thread and hope there are still a lot of VK-2100 tweakers out there.

I acquired a VK-2100 and it sounded just ok. Adjusted the mV across the center resistors per the photo and 'instructions' here, and can ONLY get them down to about 45mV each. Dont know where you all got 25mV for more class A and 15mV for cooler running, but mine will only go as low as 45mv ?!?

Replace the preamp tubes with JJ ECC 82 (12AU7) and ECC81 (12AT7) as I have a board that says it will take them. Compared to the stock Shaguang (sp?) 6N1-M's, the will barely light. The amp sounds semi-ok so far and powers up just fine, but there is hardly any light in them at all. Makes me wonder if it is ok to run them regardless if Yaqin prints 12AU7 and 12AT7 directly on the board. I realize they are probably 12v vs 6v on the 6N1's, but its a little unnerving.

I also have conflicting info from this thread. I have two photos I printed stating adjustments on the transistors. Left outside one at 1.15vdc. Inner ones at -0.68vdc. But the inner ones use the same pot used to adjust across the resistor I stated above between ~15-35mV. If you change that adjust the inner transistor to -0.68VDC you've changed what you adjusted across the resistor ?!?

 

[KKnight]

Bump*

 

[KKnight]

Ha looks like no one years after has kept or is still using their VK-2100.

But.. if so and you know what youre talking about, any other audio uses for the transformer?

 

[Poultrygeist]

I owned a VK-2100 for a short while and as I recall there was only one replacement option for the Chinese 6N1. It's the Russian 6N1p-ev and it's a decent tube upgrade.

I sold the VK-2100 as it sounded more like a solid state amp than a tube amp.

 

[KKnight]

I owned a VK-2100 for a short while and as I recall there was only one replacement option for the Chinese 6N1. It's the Russian 6N1p-ev and it's a decent tube upgrade.

I sold the VK-2100 as it sounded more like a solid state amp than a tube amp.

Depended on the board. Most of them now are for 12A*7.

Anyone anywhere know the specs on the transformer and what other cannibalized use it may have?