Wow. Yaqin MS-23B

[Nixxuz]

Just got this guy today so the tubes aren't even burned in a little. First 1/2 hour or so was good, but a wee bit muted. Must have just needed time to warm up, because it's opening in every direction. I was using an ART DJPre II, and before that a shitty $15 Pyle. Incremental steps obviously. But this is just...wow. I know it's certainly not "high end", but I'm floored. I can't imagine the sound when my gold tip Electro-Harmonix show up on Thursday.

Unfortunately, it does have the "hum". Apparently it's a design flaw...or a manufacturing flaw. It seems that some of the units have it and some don't. I hope it's cleared up after I get it in for the "LesBox" mod. Until then this box is more of a tube buffer than an actual preamp. And that mod is partially why I got it. It seems a few enterprising folks out there mod it to use a 3rd tube for...I think for the gain. Anyway, that's a stretch down the road, and I'm quite happy for now.

Oh yeah, out of the box it literally REEKS of China, or at least pollution and industry. Kind of a bummer there, but I think I just got a massive hit when I opened the box.

 

[mjw21a]

Try a pair of Raytheon Black Plate 12AX7 in there. It's the perfect tube for an unmodified Yaqin MS23B.

If you ever want to improve the unit try Googling Yaqin MS23B Lesbox mod

 

[Nixxuz]

Already spoke to both Les and his counterpart in the states about getting the mod done. I actually looked into that before I ordered it. I'll look into the Raytheons, but I will note that I'm apparently one of the few out there that has tried the newer stock Mullard's in a 6J1 preamp I'm running, and found them claustrophobic and muted compared to a set of GE JAN 5654W's. What's the sound like on the Raytheon?

 

[mjw21a]

Raytheon is extremely full bodied and liquid sounding in this circuit. Plenty of definition and dynamics though definitely not warm like a NOS Mullard or GE tube, then again not bright like NOS Russian Reflektor tubes either. The Raytheon's very circuit dependent. Magic in a stock MS23B though in other circuits can be quite hard to listen to

 

[Hi-Q]

A lot of work has been going on to make a replacement circuit board, even kitted it with miniature screw terminal blocks so you don't have to solder.
You still have to cut an extra hole for the third tube but with a template and a cheap cone cutter purchase on the internet, anyone should be able to do this too.
It is hoped to offer the PCB fully built and tested and without the heavy iron work should be a lot cheaper to post.
Of course you may opt for just a circuit board too though it may be necessary to supply the tube sockets as they are a bit special.
Order has been placed for some test boards so fingers crossed

 

[mjw21a]

Wow. That sounds like a fantastic idea. Almost wish I still had my MS23B still now.

 

[Nixxuz]

A lot of work has been going on to make a replacement circuit board, even kitted it with miniature screw terminal blocks so you don't have to solder.
You still have to cut an extra hole for the third tube but with a template and a cheap cone cutter purchase on the internet, anyone should be able to do this too.
It is hoped to offer the PCB fully built and tested and without the heavy iron work should be a lot cheaper to post.
Of course you may opt for just a circuit board too though it may be necessary to supply the tube sockets as they are a bit special.
Order has been placed for some test boards so fingers crossed

I guess I'll have to see how it pans out, but it sure is exciting. Its hard to believe, after hearing it stock, that people were telling Les Carpenter to take it out of his chain because it sounded so bad...what are those people used to hearing?

 

[Nixxuz]

Raytheon is extremely full bodied and liquid sounding in this circuit. Plenty of definition and dynamics though definitely not warm like a NOS Mullard or GE tube, then again not bright like NOS Russian Reflektor tubes either. The Raytheon's very circuit dependent. Magic in a stock MS23B though in other circuits can be quite hard to listen to

Wish I had known before I ordered the Electro-Harmonix...around the same price.

 

[Nixxuz]

I spoke too soon. Unit started developing a persistent hum around the 60,120,and 240hz areas at 75dB listening levels. Now I may need a power conditioner, but I wasn't chancing anything and just sent the unit back to good old Amazon. Gotta love that CS! I'm not sure, but I might try the Little Bear T11 instead, as all the things I was looking to do with modding the MS-23B seems to be included in that design from the get go.

 

[Ilikevinyl]

I really like my Yaqin MS-23B. I did replace the stock tubes with new Sovtek 12AX7LPS tubes. The Sovtek tubes sound more balanced, where as the stock tubes are more forward sounding. Mine doesn't hum! I'm using a 2 prong cheater plug but have the ground tab screwed onto the wall socket, wall socket is 2 prong. The sound is amazing, way better than my Cambridge 640P!

 

[Nixxuz]

Aside from the hum, I did like the sound. I'm using the refund for the 23B to pick up an MC13S, so it all works out.

 

[Lavane]

Does the 23B have a earth ground switch? The T-11 I have became quieter buy switching off the earth ground.

 

[Nixxuz]

Does the 23B have a earth ground switch? The T-11 I have became quieter buy switching off the earth ground.

Not that I know of.

 

[canton]

Sorry you had trouble with your Yaq pre I have had one for 18 months and have found it to be a very nice phono pre esp for the price.
Canton

 

[Nixxuz]

Like I said, I liked the sound, I just didn't want to deal with the hum, and the Little Bear T11 seems to have avoided the feedback based gain. I was interested in the 23B mods, but the more I made inquiries, the more it turned out to be almost the same price as the 33B which is essentially the modded 23B. And the guy who was doing the mods in the states was backed up, so then it becomes a waiting game to send it to him, a waiting game getting it back...etc. I'll probably pick up the T11 in a couple weeks and see how it compares to my faint memory of the 23B. In the meantime, I've got an MC13S ordered which should arrive next week.

 

[Lavane]

If you do get a t11, use the metal tube shields. At leased for the first tube.

 

[Nixxuz]

Yep. I also came across that thread. Probably go with the grounding wire to the shield as well.

 

[mjw21a]

Like I said, I liked the sound, I just didn't want to deal with the hum, and the Little Bear T11 seems to have avoided the feedback based gain. I was interested in the 23B mods, but the more I made inquiries, the more it turned out to be almost the same price as the 33B which is essentially the modded 23B. And the guy who was doing the mods in the states was backed up, so then it becomes a waiting game to send it to him, a waiting game getting it back...etc. I'll probably pick up the T11 in a couple weeks and see how it compares to my faint memory of the 23B. In the meantime, I've got an MC13S ordered which should arrive next week.

I believe Les has some pre-populated boards coming out where you simply unscrew the old board and slot in the new + drill a hole for the third tube. Basically replace the guts of the thing

 

[Nixxuz]

He did mention. No real idea of when that's going to happen. I also am a little not into the idea of just buying a housing and power supply for $200. It kind of seems like a person could just buy that board and a PSU and work up a much nicer wooden box...or steel or brass or what have you. Might be an idea to play with some day.

 

[mjw21a]

Ah, I thought you already had one . That changes things