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yaqin mc100b tube rolling

hi all,

ok i`m new to tube amplifiers, in fact i`ve not owned a hifi for a good few years so i thought i`d take the plunge and see whats out there.

after some pretty exhaustive auditioning and plenty of reading and research i decided to go for the yaqin amp. the rest of my system consists of.....

musical fidelity nu-vista 3d cd player
yaqin mc100b amplifier
quad 12L2 speakers sitting on target R5 stands
chord anthem2 interconnects
chord oddessey2 speaker wires (4 lengths)

i bought the amp secondhand and the tubes were worn and needed replacing.

i bought 4 x electro harmonix KT88EH`s
2 x shuguang psvane 12AX7T`s (grant fidelity matched)
i`ve bought a variety of 6sn7`s to test out. i bought several matched pairs. brimar 6sn7gty/cv1988, rca vt231, rca 6sn7gt, sylvania 6sn7gtb and shuguang 6n8p.

so far the brimar/shuguang combination is the best sounding. they give an excellent and pin point soundstage, the sound is very clear indeed, you can hear quite a way into recordings and there is very good depth to the soundstage. voices are solid and natural. acoustic guitars have a ring to them. dave gilmours guitar work on the track "where we start" off his solo cd on an island has a really beautiful tone to it with an added very slight warmth and depth. the brimars have a clear yet warm sound and sound slightly laid back. the shuguangs have a very clear up front sound and the combination of these two tubes is a pretty good matching. my only quibble is i could do with a bit more bass. i`m not saying the bass i get is inadequate, i could just do with a bit more.

i tried the brimars with the rca vt231`s. not a very good matching! way too much warmth going on here for me and lacks excitement. less detail too. mind you i will say, i listened to the xrcd recording i have of eva cassidy`s songbird and this cd has never sounded so good! but pretty much everything else i listened to didn`t really impress me that much. not sure what classical music sounds like with this combination. i didn`t think to listen to any!

i tried the sylvania gtb/rca 6sn7gt combination. not as much clarity or information as the brimar/shuguang combo but still very very nice sounding. nice deep bass, very nice soundstage, natural sounding voices. all in all a very nice sounding tone all the way through. beautiful and sweet top end too.

i tried the rca vt231/rca 6sn7gt combination. not really all that impressed. lots of information but just a bit dull sounding. lacks a bit of get up n go!

that`s as far as i have got so far in tube rolling. anyone else that has this amp have any tube combinations that works for them? also as i am new to valve amps and tube rolling, are there any other 6sn7 type tubes i should look out for?

many thanks in advance guys
grayf
grayf OP
61 posts
 
just another update. well i don`t know if it`s the psvanes 12ax7t`s or the brimar tubes still breaking in but wow! i have about 120 hours on the psvanes and about 30 hours on the brimars. the brimars are nos tubes. it`s like someone switched the light on to reveal bucket loads of detail. all instruments are like someones shining a light on them! there`s extra weight to everything too. there`s a very pleasing sense of depth to the soundstage. the highs really do reach the sky and the bass is rich and floor shaking deep! this is the combination i`ll be staying with now.

i did try the rca vt231/sylvania combination and very nice too. the sound is lighter and livelier. awesome detail and very atmospheric and a very big soundstage.

personally i prefered the brimar/sylvania combination. there`s a weightier sound on offer with darker tones which i find so satisfying. all my favourite cd`s hit the spot when i listen to them. not so good recordings don`t sound so bad either. late night listening has suffered a bit though because of the bass which is a shame, but i can live with that with whats on offer.

the rca vt231/sylvania combination is extremely good too and i`d say it`s more a matter of preference rather than which one is better. they both have their pro`s and cons

i used the same 3 cd`s to check the sounds of the tubes
grayf OP
61 posts
 
hi all,

sorry for the lengthy delay. i`ve been tube rolling this amp and now have the perfect combination and boy it`s transformed this amplifier into something extremely special!!! ok the combination of tubes are .....

shuguang treasure kt88-z black bottle x 4
rca vt231 grey bottles x 2 in v1 and v4
brimar 6sn7gty/cv1988 black bottle brown base x 2 in v2 and v3
telefunken 12ax7 smooth plates x 2

i swapped the brimars and rca`s around and they now work extremely well together. all the tubes work so well in harmony together! the sound is now perfection from top to bottom and the soundstage and imaging is breathtaking. so is the bass!!! so deep and warm with slam when needed. the sound is smooth and crystal clear all the way through and natural. the soundstage has perfect width and depth.

my whole system has perfect synergy too. i couldn`t be happier!

i hope this has helped others with this amplifier too :)

the tubes were pretty expensive but this amplifier can take it in it`s stride! a real bargain amplifier!
grayf OP
61 posts
 
oh and guys i`ve started another thread about upgrades for this amplifier. if anyone has modded this amp internally with capacitors or anything else i`d like to hear from you :)
scutterflux
14 posts
 
Nice! I also have one of these amps and it started me into tube rolling, Your fav is probably very similar to what my favorites are as well... Let's compare.

shuguang treasure kt88-z black bottle x 4
VS.
Shuguang Solid Smooth plate gekt88

rca vt231 grey bottles x 2 in v1 and v4
VS.
RCA 6sn7gt black plate bottom getter same spots

brimar 6sn7gty/cv1988 black bottle brown base x 2 in v2 and v3
VS
Tung-sol 6sn7gt (Mouse Ears, more on the smooth, well rounded imaging and ambiance with excellent detail and focused midrange...)

telefunken 12ax7 smooth plates x 2
VS
Sylvania 5751 grey-plates 80's... beat the telefunken and the sylvania 5751 black plates, rca's mullards etc, I highly recomend trying these ones out, they may give you the bass you're looking for and are still a very tight resposive tube like the telefunken...

Anyway havn't rolled in this amp since I came up with this combo as well years ago...

Enjoy
olds442111
2 posts
 
Has anyone tried any varieties of 12at7 up front in these amps? Or just too little gain?
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