LD Micro Tube, ah tubes at last. . Buff634 bypassed - Page 3

The tubes are Russian and to have them soldered into the sockets you would have to get them from LD. They are in a 8 pin chip socket so it is easy to remove them though not the first time. They have used nonconducting silicone to keep them in place for shipping so you have carefully ease them out the first time to break the bond. I have emailed LD to suggest some other method becasue this is not a good method of holding the socket in place as removing the tube that is soldered into the removeable socket could break something because it is not very easy the first time. I got an extra set of tubes for $15 for the pair just to have them. I would always suggest having an extra set on hand. They should last a very long time. I need to take some measurements on how the tube is being run but no time right now.

Ok I figured out how many hours I actually have on this amp and it is about 250 so my earlier post of 200 was a little short. Anyway I am posting this because I have never experienced an amp that has gone through so many back and forth changes. I have a number of other small amps to compare what I am hearing to put in check my sanity and verify what I may or may not think I am hearing. The amp about 4 hours ago was too warm for my liking and a little congested. Oh, not bad but it had sounded some better. So leaving it on with music playing through it as I have been doing for 7 days now, I came back after going out and listened. Again it had changed! Transparency had returned and dynamics in spades. I was listening to Love Over Gold and the soundstage, which is huge, was huger :^). There was great placement of instruments and a reality that just swept you away into the music. Again all this after earlier listening to other amps to verify what I was hearing was real. I started wondering if I would have to do some modding, which I don't feel like doing right now or just wait some more time and it proved to be time as the answer. I have no idea what other changes are instore but right now the dynamics and attack will take your head off.

An OTL can be very nice and from what I have read the Lunch Box should do a nice job. The Lunch Box is a pure tube design from input to output. The LD Micro Tube is a hybrid with a tube driver and an opamp with two 634 buffers per channel, if you choose the upgraded model, which I would. It is possible the LD Micro Tube will have a better grasp of the bass. I would prefer an all tube design, as I like tubes, but the Micro Tube does have some of the nice properties of tubes and the drive and control of solid-state, though I will qualify that a good tube design will have as much control but not as this price.

Sometimes you can get very good results running a hybrid but I prefer an all tube. I have the LD MT because of the micro tubes, which I have been curious about for some time and nothing else is available. I would prefer to have a tube buffer output. You could do this with a total of 3 tubes very easily although I would do it with four, using one 6111 for each channel as a buffer used by paralleling the two halves, which would double the output current and cut the output impedence.

I don't have the time or the place to do this but I would love to. The LD MT is a nice compromise with good drive and dynamics in a fairly small packageand good looks. The upgrade is to me, the only way to go and I wouldn't even offer the other amp with lesser resistors and one less buffer per channel. I would upgrade the cap that supplies the high voltage to the tube, just out of practice as I feel this is very important dc. What is nice is that the quality of components is very good at this price point and frankly, way above what you would normally get for even more money.

I would also like to purchase a Lunch Box but I would not want an amp restricted to high impedence headphones so the combination of the two amps would be a nice option. If only something like Sennheiser, like my HD650's were going to be used then why not the Lunch Box except I love to tube roll and I don't see much option with the LB. The LD MT does have the option, if you can solder the tubes into the socket of of an 8 pin socket, of using many 6111 type tubes from RCA, Tung-sol, GE, Sylvania and Raytheon from the late 1940's and on. I like this. It also might be interesting to bypass the buffers and use a high output opamp or maybe bypass the opamp.

The amp does possess very good drive and dynamic capabilities as it it. I may try a different duel opamp today but the only one I have doesn't really require buffers, the 8397. Also comparing the MT with detail of my SM LE and IV, I hear no loss of detail, which is nice to know and important to me and the LE gets all the details.

I am using some IEM's with it right now and it is exciting. It is a tube amp so not really suited for IEM's because there is some tube noise but with the music playing I don't hear it and don't care. A fun amp all in all. I am anxious to try some 6111 tubes and have them waiting for me back in the states. Some nice JAN Sylvania, Raytheon, older RCA and something else. Nice little tube amp to travel with. I played my HD650's to the max volume and it never distorted but was way to loud for me to listen to. I use the 15 gain setting. There is a 10, 15, 20 and 30 (not recommended). I like the 15 the best.

The LD M Tube keeps sounding better. This amp takes some time to really bloom but I am glad it keeps getting better and not up and down. It is very musical, which is what it is all about. Very nice solid bass control with my HD650's and with some IEM's right now the sound is fun.

I tried the AD8397 today but I prefer the stock opamp. There is better transparency and stage. There is a delicacy developing to this amp. I have close to 300 hours now on the amp with music running through it and I have noticed, in comparison to my other amps (my control group), there is a constantly increasing detail and transparency and as I have mentioned a number of times, drive and authority with the HD650's. I run the power supply out of the wall with no filtering, as I don't have any here and the electric is pretty poor.

There is no grain to the sound unless I am using a supply to my dac that injects this. By changing to battery supply for my dac when the power is poor the music is clean and smooth. It seems the LD Micro Tube puts out what you put in and has very little loss of detail from input to output.