[Loquah]

  Ebay.............

 
 I've just checked their's plenty of 5998 and they cost plenty of money as well.

Do you really need the 5998 for the CRACK?Does this tube improved the sound quality of the CRACK that much?
I changed the OUTPUT CAPS on my CRACK i paid $125 for 2 caps(See pictures).Does this cap improved the sound?Yes a little bit not like it's night and day diference IMO the improvement is not worth $125.I installed 23 stepped attenuator and IMO it only fixed the channel imbalanced and the attenuator it reduced the bass,is this attenuator upgrade worth it?maybe.
 If i'am going to build another CRACK i will just install the Speedball and be done with it.The CRACK's sound with the Speedball is really really good IMO no need for anymore modifications because this amp is well put together.Sorry folks!

 
Just to clarify, there are many different attenuators out there. We discussed some irregularities with the one you received (pictured) prior to the installation so I don't think it's a representative example of what's possible. I didn't notice this the first time because we were so focussed on the stereo / mono question, but if you look at the picture, the attenuator is built with some Dale resistors (plain brown with printed ratings) and various other resistors. Having used a 100% Dale resistor attenuator in my S.E.X. (and based on many other accounts from other experienced builders) I can safely say that a high quality attenuator will do a lot more than just fix channel imbalances and is probably the best bang-for-buck modification after the Speedball.
 
I agree that capacitors are a more subtle upgrade, but with a more transparent attenuator you may find that the caps are able to exert more influence on the sound of your Crack. I built a Crack for a friend recently using the MCaps (as you've used) along with some upgraded power supply caps and a Dale stepped attenuator and the results were excellent and a noticeable improvement on the already outstanding stock sound of the Crack + Speedball.

 

[i luvmusic 2]

 Pardon me for being a noob!I'am still learning about these Electronics/Diy amps.When you said TRANSPARENT does it mean less bass not forward sounding like the stock crack?These is what i've heard after i installed the Attenuator less bass the sound is more like distant and wider unless i turn the volume loud then it will sound pretty closed to the stock crack but then it's too loud to my liking.

 

[i luvmusic 2]

I do not intend to offend anyone who performed those upgrades.Pardon me!

 

[Loquah]

   Pardon me for being a noob!I'am still learning about these Electronics/Diy amps.When you said TRANSPARENT does it mean less bass not forward sounding like the stock crack?These is what i've heard after i installed the Attenuator less bass the sound is more like distant and wider unless i turn the volume loud then it will sound pretty closed to the stock crack but then it's too loud to my liking.

 
My experience with the Dale attenuators I've personally used and installed for friends is that the sound gets cleaner all around. There should be no loss of any frequency response (bass, mids, or treble), but rather a cleaner sound with more sense of detail. The stock attenuator provided by Bottlehead, although fine, sounds a little smoothed over in comparison to the aftermarket ones I've tried.
 
I think the problems you are hearing may be due to a poorly built attenuator with varying resistor brands which may mean that some positions on the dial actually sound different to others. Based on your pictures you installed an Alps pot since, did that improve things at all?
 

  I do not intend to offend anyone who performed those upgrades.Pardon me!

No, that's OK - I just wanted to balance the discussion for anyone reading it because there are multiple factors to consider - your post was completely fine.

 

[JamieMcC]

  I do not intend to offend anyone who performed those upgrades.Pardon me!

 
Your ok, I for one am just curious as to why you are not seeing better results for your efforts your results certainly do not seem to be the norm.
 
Your Mundorfs are not inexpensive caps by any stretch and are actually quiet a investment. Perhaps with a bit of combined brainstorming here we can figure out what might be limiting the performance and improvements you should be experiencing as you really should be noticing much more than a subtle upgrade here with them and a attenuator over the stock electrolytic capacitors and volume pot. Would you mind posting some details on your chain and cans used it might help.
 
I have tried a few different capacitors combinations including Solen, Mundorf, JFX, Jantzen, Hovland SuperCap, Epcos, RTI, Valab, among the more well known makes in my own Crack which is also fitted with the Valab attenuator and have always thought the Crack transparent enough to notice differences between them and having some very clear favourites amongst them.
 

 

[liamstrain]

   
Your ok, I for one am just curious as to why you are not seeing better results for your efforts your results certainly do not seem to be the norm.
 
 

 
Debatable. There seems to be a LOT of expectation bias in the capacitor/mod world that is not backed by objective measurements. His results are consistent both with my experience, and with the data I have seen. 

 

[JamieMcC]

   
Debatable. There seems to be a LOT of expectation bias in the capacitor/mod world that is not backed by objective measurements. His results are consistent both with my experience, and with the data I have seen. 

 
I'm not rising to the bait, (well yes I am and I should know better) having personally tried dozens of combination and am in no doubt to the differences. Further I don't really see how objectivity and measuring comes into it my self. Last time I checked they still didn't know how to objectively measuring pain so I guess that must be imaginary try convincing  a couple of billon people of that. 
 
Perhaps they just don't yet know yet how or what they are measuring relates in a auditory sense to what people hear that is if in fact they are measuring the right thing to start off with. Bearing in mind lots of capacitors are manufactured with differing techniques and materials would it not be unreasonable to think this does have a effect.
 
Five capacitors all the same value but made with differing methods and material its just plain impossible they can objectively measure the same which is basically what the premise is about subjective perception. More like they just don't know how or what to measure.
 
1/ Metalized film
2/ Film and alluminium foil
3/ Film and Tin foil,
4 Film and Copper foil
5/ Electrolytic   
 
Lets not even get into the different dielectric combinations.

 

[mcandmar]

That attenuator (i luvmusic 2) bought is a series attenuator, as in all the resistors are joined together in a daisy chain and as you raise the volume the resistors are removed from the circuit one by one.  Its entirely possible is has no sonic benefit over a stock pot as you basically have two dozen resistors in your signal path.
 
The ladder style attenuator (i.e. the ones that are twice as tall with four layers of resistors) switch between different sets of resistors as you change the volume, so there is only ever 2 resistors in the signal path at any given time, that's where the real sonic benefit comes from.
 
Both styles will have equal channel balance throughout the volume range unlike a stock carbon track pot.
 
As for the caps, the difference between stock electrolytic caps and ANY film cap is significant, i cant see how that change isn't noticeable.  ....unless of course you only listen to EDM or some other rubbish

 

[liamstrain]

   
I'm not rising to the bait, (well yes I am and I should know better) having personally tried dozens of combination and am in no doubt to the differences. Further I don't really see how objectivity and measuring comes into it my self. 

 
Not trying to provide "bait" - but we know a LOT about audibility and our ability to measure and compare frequency response and other acoustic traits far exceeds the human ability to perceive those differences. The biggest issue is it is hard for someone to swap new components into their amp fast enough to do true, level matched (much less blind) testing. So auditory memory and bias as the biggest factors in our subjective experience of Mods. 
 
Which is to say, I am certain you hear differences. I just question the nature of those differences. Audible (objective) vs. Psycho-acoustic. If you are of the opinion that we cannot measure audible changes to a circuit (or that we can hear things that we cannot demonstrate via measurements) though, we probably cannot have a productive conversation. 
 
I do not disagree that there are things that will affect the audible traits of an amplifier. But aside from using incorrect values (which would cause bass roll-off, especially with headphones on the lower level of impedence for the crack, and add distortion) - the audible change to a circuit from a capacitor (unless the circuit is designed very poorly, which the crack is not, or the capacitor chosen is unsuited for the intended use - e.g. ceramic caps), is very small indeed. On the order of "corrected by better level matching" small. 

Anyway - this is probably best reserved for "Sound Science" - I'm mostly trying to assure those who spend the money, make the mods, then don't hear what they were hoping to hear, that it's not that they necessarily did anything wrong. Many people do NOT have audible changes from such a modification, and frankly, in the case of the Crack where the included components are well specced and placed in a well designed circuit, there is little to suggest that they would hear ANY differences in sound quality or tonal representation, much less "night and day" ones. 

 

[JamieMcC]

   
Not trying to provide "bait" - but we know a LOT about audibility and our ability to measure and compare frequency response and other acoustic traits far exceeds the human ability to perceive those differences. The biggest issue is it is hard for someone to swap new components into their amp fast enough to do true, level matched (much less blind) testing. So auditory memory and bias as the biggest factors in our subjective experience of Mods. 
 
Which is to say, I am certain you hear differences. I just question the nature of those differences. Audible (objective) vs. Psycho-acoustic. If you are of the opinion that we cannot measure audible changes to a circuit (or that we can hear things that we cannot demonstrate via measurements) though, we probably cannot have a productive conversation. 
 
I do not disagree that there are things that will affect the audible traits of an amplifier. But aside from using incorrect values (which would cause bass roll-off, especially with headphones on the lower level of impedence for the crack, and add distortion) - the audible change to a circuit from a capacitor (unless the circuit is designed very poorly, which the crack is not, or the capacitor chosen is unsuited for the intended use - e.g. ceramic caps), is very small indeed. On the order of "corrected by better level matching" small. 

Anyway - this is probably best reserved for "Sound Science" - I'm mostly trying to assure those who spend the money, make the mods, then don't hear what they were hoping to hear, that it's not that they necessarily did anything wrong. Many people do NOT have audible changes from such a modification, and frankly, in the case of the Crack where the included components are well specced and placed in a well designed circuit, there is little to suggest that they would hear any sort of "night and day" differences in sound quality or tonal representation. 

 
lol yes the conversation is really better suited to being accompanied by a pint and a pie over a table at the local followed by some ABing of a modded and stock version it would make for a entertaining evening.
 

 

[liamstrain]

Yes it would indeed. ​Several pints and you might win me to your side.  

I actually once drew up plans for a capacitor switching board, which would allow for faster testing on the same amplifier - but I never solved a few theoretical issues (like safe discharge). But it would be interesting to do both measurement and listening tests with such a set-up, as that would help minimize some variables. 
 

 

[grausch]

  Yes it would indeed. ​Several pints and you might win me to your side.  

I actually once drew up plans for a capacitor switching board, which would allow for faster testing on the same amplifier - but I never solved a few theoretical issues (like safe discharge). But it would be interesting to do both measurement and listening tests with such a set-up, as that would help minimize some variables. 
 

Safe discharge???? What is that? Does it go well with beer? Obviously you need a few more pints.

 
In any case, I am still debating whether to buy another Crack just so that I can test these differences. Was thinking of running a Y-cable from the source and getting 2 sets of headphones. However, that introduces another set of problems, i.e. who says two of the exact same headphones sound the same? Also, we are assuming that all of the parts inside of both Cracks have been manufactured identically (highly unlikely) and have the same amount of burn-in. We are also assuming the tubes sound exactly the same. 
 
Or maybe, I should just tinker with the existing Crack, enjoy the music and save up for another amp.

 

[i luvmusic 2]

 

  I do not intend to offend anyone who performed those upgrades.Pardon me!

 
Your ok, I for one am just curious as to why you are not seeing better results for your efforts your results certainly do not seem to be the norm.
 
Your Mundorfs are not inexpensive caps by any stretch and are actually quiet a investment. Perhaps with a bit of combined brainstorming here we can figure out what might be limiting the performance and improvements you should be experiencing as you really should be noticing much more than a subtle upgrade here with them and a attenuator over the stock electrolytic capacitors and volume pot. Would you mind posting some details on your chain and cans used it might help.
 
I have tried a few different capacitors combinations including Solen, Mundorf, JFX, Jantzen, Hovland SuperCap, Epcos, RTI, Valab, among the more well known makes in my own Crack which is also fitted with the Valab attenuator and have always thought the Crack transparent enough to notice differences between them and having some very clear favourites amongst them.
 

Holly! JM  how many more CAPS do you need?I think you're  a CAPACITOR Hoarder.........

 

[liamstrain]

  Or maybe, I should just tinker with the existing Crack, enjoy the music and save up for another amp.

 
Probably the best plan. 

 

[i luvmusic 2]

 

  I do not intend to offend anyone who performed those upgrades.Pardon me!

 
Your ok, I for one am just curious as to why you are not seeing better results for your efforts your results certainly do not seem to be the norm.
 
Your Mundorfs are not inexpensive caps by any stretch and are actually quiet a investment. Perhaps with a bit of combined brainstorming here we can figure out what might be limiting the performance and improvements you should be experiencing as you really should be noticing much more than a subtle upgrade here with them and a attenuator over the stock electrolytic capacitors and volume pot. Would you mind posting some details on your chain and cans used it might help.
 
I have tried a few different capacitors combinations including Solen, Mundorf, JFX, Jantzen, Hovland SuperCap, Epcos, RTI, Valab, among the more well known makes in my own Crack which is also fitted with the Valab attenuator and have always thought the Crack transparent enough to notice differences between them and having some very clear favourites amongst them.
 

MY setup, From ACER laptop(using Foobar, FLAC)  to USB in TEAC UD- H01S(DAC) RCA out to CRACK , CRACK to HD 650 or DT880 600 ohms.
JVC XV-521 DVD Player(I know it's old but it does the job,i have this for over ten years now and still working) used for playing CD's to optical in TEAC (DAC) to crack,CRACK to HD 650 or DT880 600 ohms.
CABLES used are 3ft generic USB cable,3ft optical cable and Diy RCA cable(2ft ViaBlue NF-A7 Triple Sheild,REAN Gold plated RCA Jack)
I listened to all types of Music/Genre anything that sound good to my ears.I have about 500+ Cd's i stopped counting them long time ago i just buy and buy. 
Your not gonna tell me to upgrade my cables are you?

 
 
JVC  (Junk Very Cheap)