jonathan c
Headphoneus Supremus
*** Samuel Beckett reprise? Waiting For Mjolnot…
Schiit Mjolnir 2 Listening Impressions
Can someone plz recommend me a set of 12at7 equivalent tubes that are bassy, warm, low end heavy (almost top end roll off), like a tube that can be used to tame a analytical headphone, a tube that can smooth out top end harshness. I am trying to tune in my cap modded MJ2 with a DCA expanse.
Thank you
Thank you
ShortBtwnHdset
100+ Head-Fier
It's not a 12a type, but I've tested a GE Smoked Glass 6DJ8/ECC88 that was like that, and a Ken Rad 6414 that was similar. Not sure where you'd find the first, but DB tubes probably still has the other (Ken Rad)
Edit: Actually, the Ken Rad is a 12a pinout!
Edit: Actually, the Ken Rad is a 12a pinout!
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ShortBtwnHdset
100+ Head-Fier
ShortBtwnHdset
100+ Head-Fier
Hey Gang! It only took over a month, but my Siemens E88CC's finally arrived. They seem to be A frame type getter, gold pinned, but the flash on the top of the tubes gives me some doubt about validity. I've never seen tubes with that much flash where the tube tops come together, shows up better on the 2nd pic. What is Ya'lls experience?
I am in love with my Utopia's, did a lot of listening over the weekend, have made an initial EQ curve on them (but they sounded fantastic un-EQ'd). Settings used are the ones near the beginning of the Utopia thread, Oratory1990's. Currently listening to Dire Straits "Brothers in Arms" album , just wonderful!
I compiled and straightened out my tube collection, and I think BCowan might not scoff at it! Mostly 12AT7 types, a few oddballs like 6021 conversion projects (need soldered to adapters), 5960's w/adapters, and a much smaller collection of 6DJ8 types. Plenty to roll to my hearts content, and a few to sell or give away. I bought this Mjolnir 2 used about a year and a half ago, and all this has been collected since. Really helps that I'm only trying to outfit a HP amp that uses 1 pair of tubes! I have maybe one or two more special pair I'd like to get, we'll see.
Think I'll leave the Siemens in for now, really like their FR extension on the low end!
I am in love with my Utopia's, did a lot of listening over the weekend, have made an initial EQ curve on them (but they sounded fantastic un-EQ'd). Settings used are the ones near the beginning of the Utopia thread, Oratory1990's. Currently listening to Dire Straits "Brothers in Arms" album , just wonderful!
I compiled and straightened out my tube collection, and I think BCowan might not scoff at it! Mostly 12AT7 types, a few oddballs like 6021 conversion projects (need soldered to adapters), 5960's w/adapters, and a much smaller collection of 6DJ8 types. Plenty to roll to my hearts content, and a few to sell or give away. I bought this Mjolnir 2 used about a year and a half ago, and all this has been collected since. Really helps that I'm only trying to outfit a HP amp that uses 1 pair of tubes! I have maybe one or two more special pair I'd like to get, we'll see.
Think I'll leave the Siemens in for now, really like their FR extension on the low end!
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Moochibond
500+ Head-Fier
Hi,
Any UK based MJ2 owner here wishing to sell their amplifier?
Thanks!
Any UK based MJ2 owner here wishing to sell their amplifier?
Thanks!
ShortBtwnHdset
100+ Head-Fier
Hi All! It’s been a while, thought I might post some updates, and query a few of you on tube rolling experience.
1st, I did complete 3rd stage cap mods. No pics as of yet as it’s messy. The 4 main voltage rails (10,000 uF caps) for the output transistors were all modded, used a 220uF small electrolytic across the first cap of the CRC filter, followed by a 2.2 uF Mundorf Evo-Oil across the second cap. They have been settling in, maybe have 20 hrs on them so far. Bass texture and body have improved, and the low mids seem fuller as well. I tried glueing cut up sorbothane sheet in strips around the big caps on the underside of the amp (at cutouts), in hope that that would give extra support to those caps hot glued to the bottom side of the board. I found one of them detached from the board and hanging when I started the mod. That didn’t work out so well, was messy and the strips didn’t stay attached. Will have to reconfigure/retry.
2nd bit of news is a new (to me) purchase. Impulse bought a used tube DAC over the weekend, a Line Magnetic LM-32.
https://www.stereonet.com/au/reviews/line-magnetic-lm-32dac-review
Had most of the features I wanted (tube rectifier, common 12au7 tubes, 5 inputs, more current DAC chip, and good build quality), should arrive late next week. So, it uses a Chinese 6Z4 rectifier tube, but seems to have jumpers that allow a 6X4 rectifier to be used. Do any of Ya’ll have experience rolling 6X4’s? What are some good tubes to look out for. Also, any particularly good 12AU7’s, similar to the Brimar Cv-4033’s as a tube that punches well above its price point?
Will post some impressions once the DAC comes in, but given that stock tubes are Chinese, I probably won’t really get a good idea of it’s sound until I roll in a few NOS’s. Hope everyone has a great weekend, and Happy Easter!
1st, I did complete 3rd stage cap mods. No pics as of yet as it’s messy. The 4 main voltage rails (10,000 uF caps) for the output transistors were all modded, used a 220uF small electrolytic across the first cap of the CRC filter, followed by a 2.2 uF Mundorf Evo-Oil across the second cap. They have been settling in, maybe have 20 hrs on them so far. Bass texture and body have improved, and the low mids seem fuller as well. I tried glueing cut up sorbothane sheet in strips around the big caps on the underside of the amp (at cutouts), in hope that that would give extra support to those caps hot glued to the bottom side of the board. I found one of them detached from the board and hanging when I started the mod. That didn’t work out so well, was messy and the strips didn’t stay attached. Will have to reconfigure/retry.
2nd bit of news is a new (to me) purchase. Impulse bought a used tube DAC over the weekend, a Line Magnetic LM-32.
https://www.stereonet.com/au/reviews/line-magnetic-lm-32dac-review
Had most of the features I wanted (tube rectifier, common 12au7 tubes, 5 inputs, more current DAC chip, and good build quality), should arrive late next week. So, it uses a Chinese 6Z4 rectifier tube, but seems to have jumpers that allow a 6X4 rectifier to be used. Do any of Ya’ll have experience rolling 6X4’s? What are some good tubes to look out for. Also, any particularly good 12AU7’s, similar to the Brimar Cv-4033’s as a tube that punches well above its price point?
Will post some impressions once the DAC comes in, but given that stock tubes are Chinese, I probably won’t really get a good idea of it’s sound until I roll in a few NOS’s. Hope everyone has a great weekend, and Happy Easter!
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ShortBtwnHdset
100+ Head-Fier
Hey All! The Line Magnetic DAC came in 2 days ago. I'm really liking it, although it's far from optimized. Came with a set of JJ 12au7's and a Chinese 6z4. It was obvious after listening that the tubes were new, very hard, harsh, and 2D. After a few hours burn in, they are much better sounding. Right now it easily beats the sound of my Gungnir. There is an online review of a 10 DAC shoot-out where this was the fav, even beat out a Yggy. Don't know the set up or circumstances, could be legit or totally bogus, but I'm liking the sound on pretty terrible tubes, if that's any indication.
First, I got out my meter and a flashlight and started checking layout, values, power rail voltages, even documenting capacitors and some of the SS's side IC's. Lot of potential for modding, and I don't think I will even need to do any cutting!!!
AC rails of the secondary's are somewhere in line with what is printed on the board, will have to do a more thorough trace later to see what each rail measures after the bridge rectifier and CRC networks. High Voltage off the transformer measured 150V,where the Mjolnir 2 was around 200V, so they seem to be running the 12AU7's much softer. The HV rail is rectified by the 6Z4 tube, then goes to CRL network before being split to an HV electrolytic cap for each channel. There seems to be room around the HV electrolytics, so pretty sure I can bypass without much trouble. The coupling caps are laid out well, so should be no problem replacing. The circuit board area around the rectifier tube has two sets of solder lands with adjacent pads, so switching tubes would only require bridging one set of pads and desoldering the other set. Smart design choice! They are even marked with 6Z4 and 6X4.
I checked whether I could switch from SS to tube while playing music, and it doesn't seem to allow that, which is good with me. Still have to check if the tubes are powered up if SS is selected, and what restrictions have to be met to be able to switch (maybe no source synched?). The SS side has five 8 pin IC's (two types) that are socketed, so if alternate chip's or discrete modules are available, it should be no problem switching. A lot of small pF film caps in that area, I may or may not investigate better alternatives.
The down side to modding this will be the number of wires I have to unsolder to free up the board. It's laid out well, so IDing what goes where should be no problem.
Only issue the DAC came with is that there is some sort of goop sandwiched between the display and the glass in one small section, will need to disassemble to clean.
Made a LARGE order of tubes from Langrex, 4 pair of Brimar matched 12AU7 derivatives, and 7 6X4's from Brimar/Genelex/Philips/Matsushita/ and Tungsram (3 Brimar's). I have a set of black plate 12AU RCA's and an RCA 6X4 that should arrive tomorrow, so I should have a fun month rolling. Will need to build some stock of tubes for this quickly, tubes are getting ridiculously expensive. Then I'll start collecting parts for the Mod's, I probably don't want to take this apart twice, so will be one big kinda all inclusive mod.
Including an open view Pic of the layout that was from the Ebay auction, so Ya'll can get an idea. Will take detailed, better pics at some other time. Have a great night!!!
First, I got out my meter and a flashlight and started checking layout, values, power rail voltages, even documenting capacitors and some of the SS's side IC's. Lot of potential for modding, and I don't think I will even need to do any cutting!!!
AC rails of the secondary's are somewhere in line with what is printed on the board, will have to do a more thorough trace later to see what each rail measures after the bridge rectifier and CRC networks. High Voltage off the transformer measured 150V,where the Mjolnir 2 was around 200V, so they seem to be running the 12AU7's much softer. The HV rail is rectified by the 6Z4 tube, then goes to CRL network before being split to an HV electrolytic cap for each channel. There seems to be room around the HV electrolytics, so pretty sure I can bypass without much trouble. The coupling caps are laid out well, so should be no problem replacing. The circuit board area around the rectifier tube has two sets of solder lands with adjacent pads, so switching tubes would only require bridging one set of pads and desoldering the other set. Smart design choice! They are even marked with 6Z4 and 6X4.
I checked whether I could switch from SS to tube while playing music, and it doesn't seem to allow that, which is good with me. Still have to check if the tubes are powered up if SS is selected, and what restrictions have to be met to be able to switch (maybe no source synched?). The SS side has five 8 pin IC's (two types) that are socketed, so if alternate chip's or discrete modules are available, it should be no problem switching. A lot of small pF film caps in that area, I may or may not investigate better alternatives.
The down side to modding this will be the number of wires I have to unsolder to free up the board. It's laid out well, so IDing what goes where should be no problem.
Only issue the DAC came with is that there is some sort of goop sandwiched between the display and the glass in one small section, will need to disassemble to clean.
Made a LARGE order of tubes from Langrex, 4 pair of Brimar matched 12AU7 derivatives, and 7 6X4's from Brimar/Genelex/Philips/Matsushita/ and Tungsram (3 Brimar's). I have a set of black plate 12AU RCA's and an RCA 6X4 that should arrive tomorrow, so I should have a fun month rolling. Will need to build some stock of tubes for this quickly, tubes are getting ridiculously expensive. Then I'll start collecting parts for the Mod's, I probably don't want to take this apart twice, so will be one big kinda all inclusive mod.
Including an open view Pic of the layout that was from the Ebay auction, so Ya'll can get an idea. Will take detailed, better pics at some other time. Have a great night!!!
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blackdragon87
Headphoneus Supremus
would this pair well with atrium, aeolus or verite closed
considering picking one up, any advice appreciated
considering picking one up, any advice appreciated
ShortBtwnHdset
100+ Head-Fier
Hey Blackdragon87!
It would drive any of them well, it really is powerful! I upgraded from a Burson HA-160, with EQ it just didn't quite have enough juice to run my VO's. I was usually around 1:00 to 3:30 on the volume control. This took it back down around 9:00 to 12:00, but again, I do a lot of EQ'ing (lot of HF hearing loss) and have to take digital volume down to keep signal from clipping input. I think used price on these is around $700 to 750, which makes them a really good buy for their flexibility. I also found the SS tubes for sale online maybe half a year later. They do well for burn in after mods.
Schiit is coming out with a Class A Mjolnir 3 sometime in the next year, though. Will likely be more resolving than this. My modded one I'll never get rid of, it's my endgame Headphone Amp, but I doubt many/any will go to the lengths or expense to mod theirs like I have. I did it in stages, learned a lot, and now have an awesome setup. Most others got their use out of it and moved on to better and more expensive set-ups (I imagine), hence so little activity here lately.
As to news, I'm slowly collecting tubes for my Line Magnetic DAC. An RCA 6X4 and some RCA clear top (edit: sorry, meant black plate)12AU7's really improved my SQ level across the board. I did change the jumpers so I could use the 6X4's instead of 6Z4's. Got in a batch of tubes Monday, ran them up just to check if good, 2 standouts in the batch , a Mullard EZ90 rectifier and a pair of Valvo ECC82's, but really only gave them a song to test before I put back in the RCA's. I will do a shoot out later when several other tube packages come in.
As to the sound, this DAC is really nice! I pretty much knew my DAC was holding me back. No longer, vocals are now much more present in the mix and localization has greatly improved. It'll probably be a while before I decide to mod this, I'm just enjoying it too much to take it out of service to mod. Have to gather supplies and ideas anyway, and my first order of business right now is stockpiling tubes. Seriously think this DAC is my endgame as well.
Anyway, have a great night, all!
It would drive any of them well, it really is powerful! I upgraded from a Burson HA-160, with EQ it just didn't quite have enough juice to run my VO's. I was usually around 1:00 to 3:30 on the volume control. This took it back down around 9:00 to 12:00, but again, I do a lot of EQ'ing (lot of HF hearing loss) and have to take digital volume down to keep signal from clipping input. I think used price on these is around $700 to 750, which makes them a really good buy for their flexibility. I also found the SS tubes for sale online maybe half a year later. They do well for burn in after mods.
Schiit is coming out with a Class A Mjolnir 3 sometime in the next year, though. Will likely be more resolving than this. My modded one I'll never get rid of, it's my endgame Headphone Amp, but I doubt many/any will go to the lengths or expense to mod theirs like I have. I did it in stages, learned a lot, and now have an awesome setup. Most others got their use out of it and moved on to better and more expensive set-ups (I imagine), hence so little activity here lately.
As to news, I'm slowly collecting tubes for my Line Magnetic DAC. An RCA 6X4 and some RCA clear top (edit: sorry, meant black plate)12AU7's really improved my SQ level across the board. I did change the jumpers so I could use the 6X4's instead of 6Z4's. Got in a batch of tubes Monday, ran them up just to check if good, 2 standouts in the batch , a Mullard EZ90 rectifier and a pair of Valvo ECC82's, but really only gave them a song to test before I put back in the RCA's. I will do a shoot out later when several other tube packages come in.
As to the sound, this DAC is really nice! I pretty much knew my DAC was holding me back. No longer, vocals are now much more present in the mix and localization has greatly improved. It'll probably be a while before I decide to mod this, I'm just enjoying it too much to take it out of service to mod. Have to gather supplies and ideas anyway, and my first order of business right now is stockpiling tubes. Seriously think this DAC is my endgame as well.
Anyway, have a great night, all!
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XMarsX
100+ Head-Fier
Class A Mjolnir 3? Schiit, my Mjolnir 2 gets delivered today and I’m already excited for the 3! 
Mimouille
Headphoneus Supremus
May I ask what set of tubes you are using?
ShortBtwnHdset
100+ Head-Fier
If that question was directed at me, in the Mjolnir right now I'm using GE-6201 5 stars with adapters. Good general all around tube that's reasonably priced.
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ShortBtwnHdset
100+ Head-Fier
Hey XmarsX, are you going to run stock, or have you got somethig picked out, tube wise? Hope you love yours!Class A Mjolnir 3? Schiit, my Mjolnir 2 gets delivered today and I’m already excited for the 3!
XMarsX
100+ Head-Fier
I bought it on USAM. The original owner is including a set of Amperex JAN 7308s and a set of Ei/Yugo 6DJ8s. My only other limited experience with tubes with my new Lyr+, so to say I am ignorant about tubes would be an understatement.
UPS delivered the Mjolnir but I am stuck at work.
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