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    Building, troubleshooting and testing of these amplifiers should only be
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    the safety precautions around high voltages.

Mr. Liang audio amplifiers

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These were my stock tubes (6j4p). I haven´t tried other than Kenrad 6AC7, but for me, original sound (with 6j4p) is far better than that of Kenrads. My amp is the one with 6L6 (no 300B).

I'm going to do some low frequency decibel test between the 6J4P and 6Ж4 because it seems to be an unacceptable difference. The new tubes really did transform the amp when I was sure it was functioning incorrectly...
 
Update: The amp has really transformed itself with some more burn-in time; maybe 150 hours total. I have been switching back and forth between the NOS 6J4P and stock 6Ж4 tubes, and I no longer hear a serious difference. The 6J4Ps are a little smoother and less sterile, but the overall bass response in the amp is now strong. Gone are any hints or anemic bass or lacking lower end as previously mentioned. I'm going to roll in some Shuguang Treasure 300B tubes and see if I can improve the sound quality more, but even without making major hardware changes, this amp is sounding good...
 
Update: The amp has really transformed itself with some more burn-in time; maybe 150 hours total. I have been switching back and forth between the NOS 6J4P and stock 6Ж4 tubes, and I no longer hear a serious difference. The 6J4Ps are a little smoother and less sterile, but the overall bass response in the amp is now strong. Gone are any hints or anemic bass or lacking lower end as previously mentioned. I'm going to roll in some Shuguang Treasure 300B tubes and see if I can improve the sound quality more, but even without making major hardware changes, this amp is sounding good...

Hi Zcales-

I also have a Liang 845-3.

So far, I am very pleased with the amp- but it does seem better week after week. I am glad to hear your explanation of the burn-in.

My amp came with the 6Ж4 tubes too. Did you end up staying with those tubes?

Have you tried the Shuguang Treasure 300B tubes? I would like to have a spare set of tubes, but will probably wait until next summer to get them- still I have been interested in how these tubes would perform in the Liang 845.

Thanks in advance- and thanks for your posts!

Karl
 
Liang 845-3 Hum at Maximum Volume

When my volume is turned up all the way on my Liang 845-3, I hear a low hum. I should note that my speakers have 98.5db/1 watt efficiency rating, and I cannot hear this hum at normal listening levels.

My question is, is this hum easy to get rid of?

Or worse- is this hum indicative of some kind of problem with the amp?

I love my Liang- and it does seem to get better every day. Right now, I am planning to keep the amp the rest of my life after replacing the cheap caps and resistors.

Any ideas would be appreciated- Thanks!

Karl
 
When my volume is turned up all the way on my Liang 845-3, I hear a low hum. I should note that my speakers have 98.5db/1 watt efficiency rating, and I cannot hear this hum at normal listening levels.

My question is, is this hum easy to get rid of?

Or worse- is this hum indicative of some kind of problem with the amp?

I'll play around with my amp tonight and see if I have the same hum as my speakers are the same sensitivity as yours. Some amps just have a little hum that is not audible when listening to music and it usually doesn't mean something is wrong. Sometimes replacing the filter caps with better quality or higher value ones can reduce the hum if it is a lack of filtering issue. Also, if signal wires are running next to transformers unshielded, that may also lead to a hum.

On my amp, I have switched over to the NOS 6J4P from the stock metal 6Ж4 and am staying with the change. Not only do the glass body tubes look better, but they sound a little smoother as well. I have swapped the Shuguang Treasure 300B into the amp and the improvement was not as good as I had hoped. There was a subtle improvement in overall tone and musicality, but I feel that had more to do with the upgrade from a low quality Chinese tube, than anything else. I think even a standard Shuguang 300B tube would provide the same improvement in the amp since the 300B is not used as the output tube, but the Shuguang Treasure 300B is a fantastic output tube in a 300B amplifier that I highly recommend.

My biggest beef with the amp right now is that it is not remote control, but you can't have everything for the price. I'm glad you are liking the amp, and an upgrade to better caps and resistors to start should sound nice.
 
Thanks Zcables

.... I have switched over to the NOS 6J4P from the stock metal 6Ж4 and am staying with the change. Not only do the glass body tubes look better, but they sound a little smoother as well. .... I'm glad you are liking the amp, and an upgrade to better caps and resistors to start should sound nice.

Hi Zcables!

Thanks for the information! Next summer I am planning to get the new caps and resistors.

What brand of 6J4P tube did you settle on?

Thanks again!

Karl
 
Hi Zcables!

Thanks for the information! Next summer I am planning to get the new caps and resistors.

What brand of 6J4P tube did you settle on?

Thanks again!

Karl

I am using NOS Shuguang 6J4P tubes from 1981. That's by no means the golden era of tubes, but they do sound nice and were relatively cheap even being shipped from China.

After listening for an hour last night, I do have a buzz in my amp too that is not audible during listen. The buzz really only shows up when the volume pot is past 50%, and then it goes away as the volume increase again. The good news is that I'm never been able to get the amp over 25% volume anyway with the high sensitivity speakers, but very insensitive speakers may have an issue with buzz.
 
The buzz really only shows up when the volume pot is past 50%, and then it goes away as the volume increase again. The good news is that I'm never been able to get the amp over 25% volume anyway with the high sensitivity speakers, but very insensitive speakers may have an issue with buzz.

Hi ZCables,

Looking at the noise more carefully, mine is the same way.

With the efficiency of my system, like you- I cannot get the volume up loud enough to hear the buzz.

Have you tried Wavebourn's idea with the aluminum foil? I will do that at some point.

Thanks for the post-

Karl
 
Can The Liang 845-3 Be Modified To Allow A Preamp?

Hi Folks!

In another year I will be able to put some more money into my system.

Can the Liang be modified to accept a preamp? Back about 4 months ago I thought I read that it could, but now I cannot find the link.

I am interested in this both to possibly improve the sound, and also to be able to hook all the different stereo equipment.

What do people think?

Thanks!

Karl
 
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