[ksorota]

Hey Ksorota, your the one doing mods to the Mjolnir, right? Seems many like your upgrade. This is basically upping the capacitance in the PS's, as well as changing cap brands/series to better sounding ones. These are the caps dealing with DC ripple, right? Tied to ground and shunting noise on both the HV and LV rails?. Has anyone tried bypassing these as well or instead?

Thanks for reply in advance!

As far as I know, that has not been done. I know I have not tried this approach. I would be hesitant to change up the circuit in any drastic way as I am not sure it could take it. What would bypassing them gain you in this case?

 

[ShortBtwnHdset]

Hey Ksorota!



As best I can describe bypassing, it goes something like this. Film Caps generally have a better sound than electrolytics, mostly due to having lower ESR (electrical series resistance). But… they are more expensive to manufacture and are much larger in volume per uF of capacitance. So manufacturers use electrolytics because they are very compact and low cost, especially in power supplies where massive uF’s values are needed. So to bypass, you would use a film cap, somewhere around 1% to 2 % of the capacitance of the electrolytic cap, connected in parallel to the electrolytic. Capacitors in parallel are equal to the sum of their capacitance, so very little has changed value wise. But, you get the advantages of a better sounding film cap without the huge size/huge cost of replacing the electrolytic with a film cap, as well as better ripple filtering. I'm a little shaky on the theory, but if I have it right, the uF of a cap determines the Q of the RC circuit, the Q of a circuit determines at what freq it best shunts ripple (noise) on the DC rail to ground. By bypassing, you now have another Q freq, and a bandwidth range from one caps Q to the other where noise (ripple) passes easily. Not the best description, but I’m not an electronics whiz.



My experience with it is it makes for blacker backgrounds and clearer mids/highs. I did this on a Burson Soloist HA-160, really liked the results. But it was a b**ch to implement (Burson is very compact)! I wouldn't have been in market for another amp if it weren't that the Verites’ just demand too much power (anywhere from 12:30 to 3:30 on the volume control).


Bypassing is a bit controversial, there are detractors, but it is a practice upheld by many in the Audiophile community. It’s commonly done on electrolytic caps , especially if tied to ground.

Edit: Man, I suck at trying to describe this. Sorry!!!

 

[ShortBtwnHdset]

Hi all! Quick update, glued up my one cup on my Verite opens. Like I said, it’s going to be visible, and there’s not much I can do about it. The problem is the split up to the metal vented cap. I’m pretty sure that cap was installed with an interference fit to the cup, and therefor the crack doesn’t want to fully close, even with moderate clamping force. Looked into removing the cap, it’s just too much work and I don’t know that I could get it out cleanly, nor press it back in and glue it without making a bigger mess. The piece that broke off between vents fit up well though, that break should be invisible. Structure wise, it should be sound. I’m going to let it dry 24 hrs, then get out some hobby grade super glue/accelerant and try to fill and sand the glued crack to a smooth surface. If I’m lucky, I can spot finish to where it’s not noticeable.

In Mjolnir news, my amp should arrive tomorrow, but I won’t be able to do more than a quick listen, as the to do list before this house renovation is still massive, and I’m out of town on business all next week. I’m hoping when I get back to have 2 different tube vendor packages awaiting, fingers crossed!

Anyway, have a great night!

 

[Rowethren]

Hi all! Quick update, glued up my one cup on my Verite opens. Like I said, it’s going to be visible, and there’s not much I can do about it. The problem is the split up to the metal vented cap. I’m pretty sure that cap was installed with an interference fit to the cup, and therefor the crack doesn’t want to fully close, even with moderate clamping force. Looked into removing the cap, it’s just too much work and I don’t know that I could get it out cleanly, nor press it back in and glue it without making a bigger mess. The piece that broke off between vents fit up well though, that break should be invisible. Structure wise, it should be sound. I’m going to let it dry 24 hrs, then get out some hobby grade super glue/accelerant and try to fill and sand the glued crack to a smooth surface. If I’m lucky, I can spot finish to where it’s not noticeable.

In Mjolnir news, my amp should arrive tomorrow, but I won’t be able to do more than a quick listen, as the to do list before this house renovation is still massive, and I’m out of town on business all next week. I’m hoping when I get back to have 2 different tube vendor packages awaiting, fingers crossed!

Anyway, have a great night!

If you don't have any luck with the Verites I know ZMF do quite a comprehensive package of repairs, obviously it wouldn't be free but it depends on how happy you are with the fix.

 

[ShortBtwnHdset]

Hey Rowethren!

I probably should have considered that before repairing. At this point, glue is in the joint, so there's not much that can be done on their end, other than replace the cup (Zircote). That would depend on wood availability. Guess I'll have to save up and get a replacement set of Verite's at a some point. For now, I'll use what I have. Thanks for the suggestion!

 

[Rowethren]

Hey Rowethren!

I probably should have considered that before repairing. At this point, glue is in the joint, so there's not much that can be done on their end, other than replace the cup (Zircote). That would depend on wood availability. Guess I'll have to save up and get a replacement set of Verite's at a some point. For now, I'll use what I have. Thanks for the suggestion!

I think they can do full cup replacements but yeah it would depend on wood availability. This is the price breakdown:

 

[ShortBtwnHdset]

Hi Gang, finished up the Verite cup today, looks very good. There's some places I went thru the finish, but these were used headphones with a lot of wear, so I'm good with it for now.

AND, an expected guest arrived, currently warming up! Trying it with the tubes that were already on the adapters.
I'll probably get the Verite's assembled tonight, b ut I won't have a balanced cable for them made until this weekend.

Ya'll have a great night!

 

[Smoothstereo]

Hi all,

Anyone able to compare the Brimar CV455 KB/FB from 1956 to the Brimar CV4024 KB/AD circa 1950s and to RCA Cleartop 12AU7 from circa early 1960s ? I have the latter two tubes, would like to know how the Brimar CV455 performs in comparison.

Thanks.

 

[bcowen]

Hi Gang, finished up the Verite cup today, looks very good. There's some places I went thru the finish, but these were used headphones with a lot of wear, so I'm good with it for now.

AND, an expected guest arrived, currently warming up! Trying it with the tubes that were already on the adapters.
I'll probably get the Verite's assembled tonight, b ut I won't have a balanced cable for them made until this weekend.

Ya'll have a great night!

That's a very interesting Loki Max. An equalizer with tubes would be the bomb.

 

[ShortBtwnHdset]

Hey All!
Bcowen - I did notice that but didn't realize what the Loki referred to. I guess the seller is selling all his Schiit! lol

Bit of news, tried the tubes last night, The CON ones attached to bases had a channel out, the ones with orange lettering didn't work at all with bases so I'm using what I assume is the stock 6DJ8's with no riser. Sounds OK, but underwhelming by what I know tubes can do. So now I'm questioning both the risers and the other tubes. No markings on the risers, all I know is they are for 9 pin tubes. So to be sure, ordered a set of the converters from Pulse (6DJ8>12AT7).

Did some looking online at pin layout for 12A's and 6DJ8's, the only difference I can tell seems to be the 6DJ8's have pin 9 as a shield between sections

and the 12AT7 seems to have pin 9 as a center tap for the heater, with no shield.

I'm guessing here, but that center tap might be because 12a's can be either 6 or 12 volt heater config?

Hmm, if the shield is actually used in our Mjolnir's , I think it might have some advantages (crosstalk/lower noise). Further reading revealed this tube type was not really made for audio applications, but Schiit chose that tube for a reason. I might have to look at getting a few HG 6922/ECC88/6DJ8's!

No progress on the cable, and I haven't assembled the ZMF's. XLR connector didn't come in. I'll be too busy for the next week to work on it, so will have to shelve until next weekend.

Anyway, hope Ya'll all have a great weekend!!!

 

[ksorota]

Hi Gang, finished up the Verite cup today, looks very good. There's some places I went thru the finish, but these were used headphones with a lot of wear, so I'm good with it for now.

AND, an expected guest arrived, currently warming up! Trying it with the tubes that were already on the adapters.
I'll probably get the Verite's assembled tonight, b ut I won't have a balanced cable for them made until this weekend.

Ya'll have a great night!

Wow, excellent job with the repair! If you didnt point it out, it would be hard to tell at a passing glance. I have seen sets of other lighter woods that looked more like they were cracked than your set.

 

[bcowen]

Hey All!
Bcowen - I did notice that but didn't realize what the Loki referred to. I guess the seller is selling all his Schiit! lol

Bit of news, tried the tubes last night, The CON ones attached to bases had a channel out, the ones with orange lettering didn't work at all with bases so I'm using what I assume is the stock 6DJ8's with no riser. Sounds OK, but underwhelming by what I know tubes can do. So now I'm questioning both the risers and the other tubes. No markings on the risers, all I know is they are for 9 pin tubes. So to be sure, ordered a set of the converters from Pulse (6DJ8>12AT7).

Did some looking online at pin layout for 12A's and 6DJ8's, the only difference I can tell seems to be the 6DJ8's have pin 9 as a shield between sections

and the 12AT7 seems to have pin 9 as a center tap for the heater, with no shield.

I'm guessing here, but that center tap might be because 12a's can be either 6 or 12 volt heater config?

Hmm, if the shield is actually used in our Mjolnir's , I think it might have some advantages (crosstalk/lower noise). Further reading revealed this tube type was not really made for audio applications, but Schiit chose that tube for a reason. I might have to look at getting a few HG 6922/ECC88/6DJ8's!

No progress on the cable, and I haven't assembled the ZMF's. XLR connector didn't come in. I'll be too busy for the next week to work on it, so will have to shelve until next weekend.

Anyway, hope Ya'll all have a great weekend!!!

Yes, the Pin 9 center tap for the 12A*7 is for the heater wiring configuration. But from a heater voltage perspective, it should work either way for the dual voltage 12AT7. I would suspect the adapters are not for a 12A*7 -> 6922 application. Could be meant for a 2C51 (396A) up top, or a 6N3P, or ??. But I'm just guessing.

 

[ShortBtwnHdset]

Do you think I could find out with my DMM? Ill try looking at those tube pin outs as well and see what my meter shows.

 

[ShortBtwnHdset]

Wow, excellent job with the repair! If you didnt point it out, it would be hard to tell at a passing glance. I have seen sets of other lighter woods that looked more like they were cracked than your set.

Thanks! Dark wood helps, but I still wonder if there's damage I can't see. No easy way to tell.

 

[bcowen]

Do you think I could find out with my DMM? Ill try looking at those tube pin outs as well and see what my meter shows.

You could see which top pin goes to each bottom pin easily enough with a DMM. That would at least tell you if it's wired for a 12A*7 on top or something else.

2C51 / 5670 / 396A below....just posting it as it's another popular type for tube rollers.