The Mjolnir 2 thread

Great pairs of Amperex tubes that have been mentioned here, in CDN dollars...

http://www.canuckaudiomart.com/details/649327374-amperexsiemens-6922/

 

So with the help of gentleman @Garns I found a pair of W396a's for my Mjolnir2. I'll do my own summary of the tubes I've tried for Mjolnir2 with HD800 but I have to say this was a very well $90 spent. As he and @philipmorgan has reported this tube will enhance soundstage depth significantly.
I did get the same effect from the LM Ericsson 2C51, and I'd say they sound very much alike.
Thanks for all help, I'm done rolling

 

Please note that these tests have all been made with Schiit Yggdrasil fed via AES-XLR (Lynx AES16 PCI) to Mjolnir2 balanced via Linn Silver XLR cables and finally to the SuperDupont modded HD800 and with Sennheisers stock balanced cable. Synergy might be more important than tube rolling…

The aim of this experiment was to achieve the following two personal objectives:

1. Keep the HD800 + Mjolnir2 soundstage together a bit more.
2. Balance between technicality (speed, accuracy) and engagement (warmth, richness)

I was lucky enough to purchase most of these pairs for far lower prices than usually seen at eBay, Upscale Audio and Brent Jesse. I’ve been around to radio museums & visiting odd auctions and old radio stores. The risk is of course that I’ve bought untested, unmatched pairs. That might have affected the performance of the tubes thus also my impressions.


Final Mjolnir 2 Tube test (stick them in, listen for a couple of days, repeat):

1.Philips Miniwatt E188CC SQ (Gold pins)

Very accurate and fast. Technical tube #1. Does everything right, but can be perceived as a bit dry and boring. High resolution, but maybe slightly light on bass. It did not tame Rudy van Gelders recordings to the full extent. Trumpets were always on the edge. Never piercing but close to. For classical music, this is a fantastic choice and if that was the only genre I listened to, I would stay with this tube and be done with it.​

2. Siemens E88CC (A frame, metal stamp date code, late 1960 - 1970).

Wet and warm. Brings the soundstage together in a very nice way. This is a pure 50’s-60’s-jazz-kind-of-tube. Absolutely dead quiet and scary black. Compared to the E188CC this is on the opposite of technical. Lacks precision and speed. If you’re into details, this might not be the choice for you. Handles treble well, but that bleeding wetness in the bass might sound muddy to some. $60-80 is probably what I’d limit myself to for a good pair. I believe the 60’s version of this is more expensive and I haven’t heard it. If you’re a Blue Note Records type person, this is your tube.​

3. LM Ericsson 2C51 (steel pin), O-getter. Requires adaptor (ECC88/6922 socket to 6N3/5670 socket):
http://www.ebay.com/itm/191636111735?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

The LME’s are just fantastic tubes. They bring the soundstage depth together nicely. It’s fun sounding yet has technical capabilities like the E188CC’s; speed, accuracy and precision. It’s not as strict as the E188CC’s and again if you’re into classical only and can find that Philips tube set for a decent price, go for it and you’ll be happy!​

4. LM Ericsson 2C51L (gold pin) One of them died on me before I managed to note my impressions.

5. Western Electric W396a. Requires adaptor (ECC88/6922 socket to 6N3/5670 socket):
http://www.ebay.com/itm/191636111735?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Like the LM Ericssons it brings depth to the table, which may be the only weakness I’ve found with the Mjolnir2. The bass is slightly laid back but not muddy. This tube is in between the Philips E188CC and the Siemens E88CC (A frame, 1970’s); the Philips being the technical master and the Siemens the midnight-fun-jazz-and-smoke-king. I would have a very hard time hearing any differences from the LME, at least it’s not obvious that one is better than the other. I won’t go back and forth between the two pairs and I’ll keep both pairs. My advice is: get the pair you can find cheaper.​

6. Philips Miniwatt E88CC SQ (1963)

Similar to the Siemens E88CC. Fun, engaging, warm, rich. Not as quiet as the Siemens, a bit more aggressive, perhaps a bit more resolution and detail vs the Siemens, but not as much as the E188CC. It might be because of the actual pair I bought. This can probably be found cheaper than the Siemens E88CC. If you find both, go with the cheaper one and you’ll save some $.​

7. Amperex Bugle Boy ECC88 (6DJ8)

I would be happy with this one if I had not heard the others. It's a typical workhorse tube. I wouldn’t pay more than maybe $40 for a pair. My tubes are not matched and from different years.​

8. Reflektor 6N3P-DR. Requires adaptor (ECC88/6922 socket to 6N3/5670 socket):
http://www.ebay.com/itm/191636111735?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Bought this matched pair for $12. During the first hours and days this sounded similar to the LME 2C51 but after a couple of days the effect wore off and it started to sound boring and almost distorted. Bought cheap but I would recommend staying away from this one.​

Ranking high to low:

1. Western Electric W396a or LM Ericsson 2C51 steel pin. I can’t say either is better than the other. If you have $100 to spend on tubes, this is the one to get. It’s worth saving up a bit instead of nervosa tube rolling.
2. Siemens E88CC. Such a great tube this is. I would love to try the early sixties version. I’m a big jazz collector and this will forever be my late Saturday night jazz session tube set.
3. Philips Miniwatt E188CC SQ. Classical maestro. Enough said. It doesn’t do anything wrong.
4. Philips Miniwatt E88CC SQ. It would’ve come up second if it would’ve been a bit more quiet, but that might be because of this particular pair. To my ears very close to the Siemens tube. If you find this one at a good price, get it. Don’t go spending $100 on it, stay below $45-50 for a pair and prepare to wait.
5. Amperex Bugle Boy ECC88 (6DJ8). It’s all good. Classic tube sound. Stay patient and you can find this for very decent prices.
6. Reflektor 6N3P-DR. It turned out to be worse than I first thought. Initial impressions were close to the LME’s but after a couple of days something happened. Can’t recommend this.

But here’s the thing and I believe this is KEY:

Mjolnir2 and either of the top 5 tube pairs in my list will make you happy all day long, and for a foreseeable future. I would have been satisfied with any of these if I hadn’t stumbled over them cheap.

My advice is: don’t go crazy tube rolling but don’t cheap out on tubes for Mjolnir 2. I was very lucky to find lots of great tubes for very good prices. The only pair I paid current market price for was the W396a (just below $100). There’s a lot of great tube reviews here on SBAF. Read carefully and feel free to start a conversation with me if you have specific questions on tubes for Mjolnir 2. Then decide on a pair and go for it.

EDIT JAN 28: I've taken out the Superdupont Resonator mod and will keep the 396a tubes running for some time.

 

I have a few pairs of tubes now but I'm horrible at comparing.

I could send them out to someone more knowledgeable/articulate than I am if it wasn't for too long.

 

Has anyone tried these tubes? Supposedly the W396a were a prototype for them? I ask because the 396a's seem to be a bit hard to find and rather expensive. Cheapest I've seen has been about $120 for a matched pair.

http://www.ebay.com/itm/5670-W-2C51-New-JAN-G-E-Tube-eq-Western-Electric-396A-/380151677912

 

Hah, I already ordered them. Unfortunately the eBay seller for the 396a adapter is out of town, so I won't be able to order that until Feb. 1.

 

The other option is to look for a pair of LM Ericsson 2C51. They're getting pricey but I can't hear any difference from the WE 396a.
You should be able to find a good pair for less than $80.
Or just be happy with the JAN's. See quote from @philipmorgan above.

 

Nice comparison. I ordered a pair of the Phillips miniwatt E88cc from Holland a couple weeks ago. The RCA branded Siemens I have in right now are a bit on the dark side

 

How do you all feel about using a SE source via RCA into the Mj2 and then going balanced out to headphones via XLR. Am I ruing the sonic performance by not feeding the amp a balanced signal?

 

A couple of quotes from the past 10 pages of this thread below. I'm sure there's more to find...

 

In my direct experience with the Mjo2, no you are not ruining the performance by using SE. Decreasing it? Sure, maybe a bit. Ruining it? No.

EDIT: The table at the bottom of http://www.superbestaudiofriends.or...ompendium-guide-to-schiit-amps-headamps.3058/ is worth a glance if you're comparing the Mjo2 to the Lyr2.

 

I'm talking about the DAC end of things. I plan to run balanced cables with my headphones but I wanted to know how much of a quality hit I could be taking by using a single ended DAC. I have a Modi Multibit currently and I don't have the cash for a Gungnir Multibit.

 

The subsection "Balanced Inputs from Sources with Balanced Outputs" at http://www.superbestaudiofriends.or...iscussion-for-noobs-and-boobs.733/#post-18920 outlines some worthwhile considerations.

 

@Changeling, everything you linked to is related to SE vs. balanced output, not using SE input to balanced output, which is what @TheIceman93 was asking about.

Mjolnir 2 converts SE input to balanced. If we're talking about Schiit DACs as an input source, my understanding is that the balanced outputs will have double the voltage of the SE outputs, but using the SE DAC outputs doesn't have a negative impact on the sound quality beyond the fact that the voltage is half of what it would be from the balanced outputs.

On the other hand, using the SE outputs on the Mjolnir 2 does have a negative impact on the sound, beyond the reduced voltage. That's because to output SE from the Mjolnir 2, there's additional circuitry to sum the balanced outputs to create the SE output. To put it more simply, if you don't have headphones with balanced cables, or don't intend to go that way down the road, Mjolnir 2 is probably not your best or most economical choice. That said, my Mjolnir 2 still sounds pretty amazing with SE cabled headphones.

I have the same question as @TheIceman93 regarding Schiit Freya, it will accept SE input and convert it to balanced when using the tube gain stage, but is there a negative impact to doing so, beyond the fact that the input is half the voltage of a balanced input (from the same Schiit DAC).

 

having tested the single ended inputs vs balanced, as well as testing the Bal vs SE headphone outputs, there is a noticeable lack of clarity in comparison. If you're going to use the M2, balanced input/output is definitely recommended.

 

and as far as the SE dac outputs, I haven't really noticed any difference in detail/sound quality running my Gungnir Multibit balanced in the M2 or single ended into the ampsandsound Kenzie. Overall, I prefer the Kenzie setup.

 

Too quick on the search and quote and reply. My bad

 

I was afraid this was going to be the case.

 

What 'phones are you running?