[s1rrah]

Quote:

Hi. What is wrong with the 2C51 label? The military Bendix Red Bank labeled 2C51 is available for $100. Is it worth?

The 2C51 is also a very excellent choice ... generally, it shares all the finer qualities of the 6385 tube (which costs more). I found the two tubes to sound very very similar. And yes, I think it's worth the asking price of 100 dollars. Either that or the JW WE396A would be excellent replacement tubes without breaking the bank.
 
Best...
.joel

 

[robeeert1]

Quote:

The 2C51 is also a very excellent choice ... generally, it shares all the finer qualities of the 6385 tube (which costs more). I found the two tubes to sound very very similar. And yes, I think it's worth the asking price of 100 dollars. Either that or the JW WE396A would be excellent replacement tubes without breaking the bank.
 
Best...
.joel

Bendix 2C51 is a very good tube,  but not as good as 6385. Is it worth a hundred? I think not.
 
 
 
 
 
 

 

[Pingfloid]

.

 

[kendrab]

I have been gathering info on modifying the Mdht Labs Havana Dac for a while. I like what people are saying about the modified versions. A round of purchases from here and on e-bay has got me pretty close.
 
I am trying to build to a pretty high standard. This means I am using Blackgate capacitors wherever possible. I have the larger capacitors all on hand, and am just left to sort out the 0.1uf and 0.22uf ones.
 
I see that some people are replacing the 0.1uf capacitors with Auricaps, and some are leaving them alone. I am wondering if the people who changed them out can comment on what that change gave them? Is there an added benefit to using a higher quality capacitor here, or is a minor upgrade to an Auricap XO or Hovland Supercap good enough?
 
I see quite a few people are using the Mundorf Silver in Oil or Silver Gold in Oil to replace the stock 0.22uf250VDC capacitor. I have heard some great things about V-Caps CuTF capacitors, so am going to see what it can do here. It is pretty pricy, but hopefully it will be worth it.
 
I am initially using a set of V-Cap OIMP 2.0 uF 250VDC output capacitors. I might eventually try using a pair of V-Cap TFTF or CuTF 0.068uf 600VDC capacitors as a bypass as per V-Cap recommendations.
 
I am going with a set of WBT 0234 Right Angel PCB based Female RCA connectors to replace the OEM audio out connectors, and have a Vampire Wire Right Angle PCB BNC connector to replace the standard right angle RCA connector.
 
I will have the parts all together this month, and will be taking it in to be professionally modified at my friend's electronic repair shop in early April. I should have it all together by mid-April, and then will give it a couple of weeks to break in.
 
As a side note, I replaced the generic power cord I was using with this dac for an Audio Art 2 meter Power 1 cable, and the diffference was not subtle. It helped both the bass and treble regions, and made the sound noticeably more cohesive. I know some people swear by very high end power cables, but this one comes in at under $200 and is very well built (and is built in the USA to boot).

 

[loserica]

Quote:

here is my list in order of importance:
1) Chips 2) tube 3) shinkoh res. 4) r-core 5) output caps 6) electrolytic caps 7) foil small caps 7) silver mica caps 8) diodes vishay 9) fuse

 
I think the order is justified and well punctuated, the only explanation, I have not tested it yet the R-Core. Already knowing that Havana react positively to a better power supply, I think it will be a major change!
 
Quote:

I have been gathering info on modifying the Mdht Labs Havana Dac for a while. I like what people are saying about the modified versions. A round of purchases from here and on e-bay has got me pretty close.
I am trying to build to a pretty high standard. This means I am using Blackgate capacitors wherever possible. I have the larger capacitors all on hand, and am just left to sort out the 0.1uf and 0.22uf ones.
I see that some people are replacing the 0.1uf capacitors with Auricaps, and some are leaving them alone. I am wondering if the people who changed them out can comment on what that change gave them? Is there an added benefit to using a higher quality capacitor here, or is a minor upgrade to an Auricap XO or Hovland Supercap good enough?
I see quite a few people are using the Mundorf Silver in Oil or Silver Gold in Oil to replace the stock 0.22uf250VDC capacitor. I have heard some great things about V-Caps CuTF capacitors, so am going to see what it can do here. It is pretty pricy, but hopefully it will be worth it.
I am initially using a set of V-Cap OIMP 2.0 uF 250VDC output capacitors. I might eventually try using a pair of V-Cap TFTF or CuTF 0.068uf 600VDC capacitors as a bypass as per V-Cap recommendations.
I am going with a set of WBT 0234 Right Angel PCB based Female RCA connectors to replace the OEM audio out connectors, and have a Vampire Wire Right Angle PCB BNC connector to replace the standard right angle RCA connector.
I will have the parts all together this month, and will be taking it in to be professionally modified at my friend's electronic repair shop in early April. I should have it all together by mid-April, and then will give it a couple of weeks to break in.
As a side note, I replaced the generic power cord I was using with this dac for an Audio Art 2 meter Power 1 cable, and the diffference was not subtle. It helped both the bass and treble regions, and made the sound noticeably more cohesive. I know some people swear by very high end power cables, but this one comes in at under $200 and is very well built (and is built in the USA to boot).

@kendrab,
Auricaps are certainly better than stock-film (0,1uf/0.22uf) capacitors. They offer a superior sound texture. But, as said Robert, electrolytic (and add, film) capacitors have a somewhat secondary importance as a direct impact on the sound quality compared with these changes: Chips - K grade, tube: Bendix 6385 from 1964, Shinkoh Tantalum res., R-Core and output-caps. On the other hand, Havana reacts pozitively to change connectors with top models (like WBT), and this is not very critical change, also. About bnc conector can say the same thing. But I cannot imagine Havana without them..
I do not know what to say about the V-Cap TFTF or CuTF capacitors(as a bypass OIMP's). Although I am concerned the problem capacitors input / output, also. I am thinking more and more, a superior solution instead of OIMP's capacitors! So I was thinking to change them with Mundorf SUPREME Silver/Gold (SGOi). Who can help? I can not tell if in our case, V-cap TFTF/CuTF really worth the price inside Havana (!?..)
 

 

[loserica]

Quote:

Probably the effect of the tube will be much better if I will replace the output capacitors V-Cap OIMP with Mundorf SUPREME Silver/Gold/Oil.. I think there is a direct synergy between the tube and the output capacitors. If I have choose Mundorf, it would be an idea to change the 0,22 uf capacitor, also (with Mundorf Supreme). I have already the R-Core, but still waiting .. and after that, a well-deserved break.
I noticed that Bendix 6385 sounds great on jazz and classical music (with Stax)...and, after about 20-30 hours, I confirm that the differences between WE (JW)396A and Bendix 6385 (from 1964) are huge!!! WAW!

audition raised to another qualitative level.

Few words about Bendix (after about 50 hours): the strangest but very nice thing that happened is the increased resolution, while keeping body and weight in sound! I noticed something for stringed instruments like guitar, violin, viola, harp, piano.., string sound not too far detached from the body of the instrument. This is related to what I remembered, instruments and voice have more body than before, although the resolution, transparency of  sound and details are better. For example,  piano sounds very clean, clear, crystal sound. sounds, ambient noises are dying slow, progressive (improved decay). WE (JW)396A wasn't capable of it.
The sound acquired a good stage positioning of instruments, a clearly perceptible layering and consistency in play (very coherent).
In parts of jazz, Bendix reveal what it is capable: the saxophone has body and transparency as well. Sound is warm and refined (obviously, the sound texture have raised to another level). Here is much "air" in the atmosphere listening.
Percussion is well emphasized, with lots of details, very good separation between instruments and different frequencies.
I am very, very pleased.

 
 

 

[mako44]

Back from holidays ! And I receive my new amp soon, great ! I wanted to buy the 6385 bendix tube but it was not available, for the moment my favourite one is the 2c51 ericsson from 50's which is very clean and opened with a very nice overall sound compared to the other ones I heard : very nice soundstage, depth, details and so on. JW we396a (1949)  is great too but too warm for me, however I understand why people love it, its sound is nice and can give a kind of magic to the music. I also tried the GE 5 stars 6386 (not JJ) but didn't like it that much : it's a kind of JW we396a, a bit less warm, but not as good as the western tube in many aspects. I would say we396a to be more refined. Both are much better than the stock tube anyway.
 
Regarding silver mica input caps can you tell me how you installed them as I saw one of the holes is too small to fit the cap into whereas the other hole is large enough (horizontal). There is another horizontal hole, unused, just below the c14 engraved number, is it possible to sold the silver mica in this unused hole or do I have to enlarge the "original" hole ?

 

[robeeert1]

Makko,
Do not enlarge the original holes! Use extension wires which fit the holes and solder the silver mica caps to them.

 

[mako44]

Thanks Robeeert, I don't like to do that a lot as extensions are not really a part of the component (not the same material for example) and I guess contacts and conductivity are not as good as only one component but well no choice here...

 

[mako44]

Done but **** I broke two copper foils around the holes... I wanted to go too fast and they've been away desoldering...

 For the moment I don't hear obvious problems in the sound, I hope it's not too important.

 

[robeeert1]

Quote:

Done but **** I broke two copper foils around the holes... I wanted to go too fast and they've been away desoldering...

 For the moment I don't hear obvious problems in the sound, I hope it's not too important.

It is not important if the circuit is not broken off. Check all connections around.

 

[mako44]

Well for the few I see it doesn't look broken. I didn't have the time to listen to it long but it sounds ok hopefully. Next step : 0.1 uf film caps when I receive them !

 

[Pingfloid]

I have started testing an unused Raytheon CK5670. With only a couple of hours burning, the highs are more harsh than a veteran GE 5670. I will let the Raytheon burn for a couple of days befor futher consideration.
 
Anyone has experience comparing the Raytheon CK5670? In the list from Mhdt it is considered 2^nd class, above the 3^rd class GE 5670. So I hope that the sound will improve.
 

 

[robeeert1]

Quote:

I have started testing an unused Raytheon CK5670. With only a couple of hours burning, the highs are more harsh than a veteran GE 5670. I will let the Raytheon burn for a couple of days befor futher consideration.
 
Anyone has experience comparing the Raytheon CK5670? In the list from Mhdt it is considered 2^nd class, above the 3^rd class GE 5670. So I hope that the sound will improve.
 

If you do not like it "at the first sight", the tube is not for you.
 

 

[s1rrah]

Quote:

If you do not like it "at the first sight", the tube is not for you.
 

I would tend to agree with that. 
 
BTW Pingfloyd... have you tried any other tubes other than the Raytheon? I personally have never heard the Raytheon tubes. Only tubes I've heard are the JW396A and the Bendix tubes (2C51 & 6385) ... I've liked them all. I also think the stock tube is okay...I mean, it doesn't sound real bad or anything...but the Bendix and the Western Electrics sound much better to my ear.
 
Good luck.