It had to happen eventually... capacitor upgrade question for the Mainline

[PassionForSound]

Hi Lachlan

I purchased a pair of the Jantzen Superior 15 uf capacitors based on your recommendation. Any tips for how you installed and secured them, as they're much larger than the previous capacitors there!

Thanks
- Alex

Hi Alex,

Sorry about my slow response - I'm not here (or on other forums) as often these days. The Jantzens are a bit tricky to install. I ended up using cable tie anchors (the adhesive squares with the flat holes to take cables ties through them) and then attached the caps using a couple of cable ties joined together for length. The caps themselves then sit snugly between the 6c45pi boards and the transformers, but are not held in by the boards which is why the cable ties are necessary.

I've attached and artsy photo to show where they sit (but not how they are held in place)

 

[mercury128]

Hi Alex,

Sorry about my slow response - I'm not here (or on other forums) as often these days. The Jantzens are a bit tricky to install. I ended up using cable tie anchors (the adhesive squares with the flat holes to take cables ties through them) and then attached the caps using a couple of cable ties joined together for length. The caps themselves then sit snugly between the 6c45pi boards and the transformers, but are not held in by the boards which is why the cable ties are necessary.

I've attached and artsy photo to show where they sit (but not how they are held in place)

Thanks Lachlan - sounds like I did similar as I also used some cable ties and anchors to get them in there. The Jantzen's sound pretty good so thanks for the recommendation. Keep up the good work on your Youtube channel!

Thanks
- Alex

 

[Toobuzz]

I got around to playing with caps on the Mainline and wanted to share my impressions along with some below average pictures, and pose a question to the community.  I have some cable tie anchors on the way, but I have a surplus of 3M Dual Lock (think non-gendered Velcro but on steroids) which actually works pretty well.

Obbligato Ultra Premiums:

I used the .1uf/1000V and the 10uf/1000V and I changed them out at the same time.  @ 100 hours, I can't say that my impressions changed over that time.

• Much bigger difference that I anticipated caps would make
• Smooth and gooey, made the Mainline sound like a Crack (not really, just in that direction)
• With well-mastered modern recordings (non-acoustic instruments/vocals) goose bumps are common and my jaw hit the floor many times.
• With acoustic instruments/natural environment recordings, I am missing the fronts of the notes.  I am missing clarity.  Classical music just sounds mushy.
• Like above the bass and dynamics in general are really lacking for acoustic instruments.  The more musicians on stage the more diffuse this all sounds.
• My goodness, the 3 dimensionality is on another level when listening to pop and hip-hop (Sam Smith, Kendrick Lamar, Taylor Swift (listening for the mastering not the content  :-[))
• It is so odd that the 3D quality is gone with classical music.  Sounds like just another diffuse tube amp

My vision for the Mainline is to highlight it's neutrality.  While the Obbligato's were a nice journey (for very little $$$), this sound is not what I want for my Mainline.

ClarityCap CSA:

One of my goals in this initial fourrée was to try and determine the effect of using 15uf vs 10uf coupling caps.  I left the .1uf/1000V Obbligatos in place as I only purchased the 15uf/250V ClarityCaps.

• Again not a big change after the first 25 hours, which is why I feel OK posting some pre-mature impressions
• Bass is more extended.  I dislike that term. I mean that I can hear the bass region louder with slightly more detail than on the Obbligatos.
• The clarity in articulation is much better.  It is still a little more diffuse that I remember the stock caps sounding, but this could very well be the .1 uf Obbligatos that are still there.  In fact, I believe that I am hearing the Obbligatos based on that specific characteristics I am hearing.
• While it might seem that I have arrived at a nice combination, the total result is much less that the sum of its parts.  On the HD800 (stock) this combo sounds very similar to the Garage1217 Ember.  I can usually pick out the Mainline due to the size of the room vs. the space between the instruments.  Either the Ember is really good with 800 (it was my first time pairing them), or this cap combo is robbing the Mainline of some of it's best traits. I can pick out the Mainline now mostly due to that slightly diffuse articulation.
• Weight.  While I have most of the articulation back, the weight of each attack is now subdued.  Perhaps another reason why this sounds so similar to the Ember?

I'm most likely going to pull the trigger on the .1 uf CuTF V-Cap, but I am still wanting some opinions on 10uf vs 15uf for the coupling caps.  I have access to a Mainline with these V-Caps (he has the 10uf V-CAP ODAM) and I like what I hear.  Based on my experiences, I may go with the 15uf V-CAP ODAM but I wanted to see if anyone had any objective feedback.  Does moving to 15uf change the frequency response?  If so, in what areas?  Or maybe the differences between 10uf vs 15uf on the Mainline is purely subjective.  I'm curious as to other's experiences in this area.   

 

[Paul Birkeland]

It's not a huge difference between 10uF and 15uF.  After reading 2/3 of your post, my initial reaction was to recommend the ODAM, so I think you're on the right track.

 

[AllanMarcus]

I was emailing about caps with a frind of mine (crack owner), and here's what he thinks. Any of this make sense?

Are these the capacitors in series just before the output?  If so, the capacitors form a high-pass filter with the load of the headphones.  See picture.  The cutoff frequency (where the power is attenuated by 1/2 or 3 dB) is 1/2piRC.  So if the headphones are 150 ohms and the coupling cap is 10uF, the cutoff frequency is about 100 Hz.  A 20uF cap drops the cutoff to 53 Hz so you'd hear more of the very low end.

 

[Paul Birkeland]

There's an output transformer, so that diagram does not really apply in that way.

 

[Toobuzz]

Thanks for the response PB!  I wanted to put down some listening notes while it was still fresh in my head, sorry for the long post. In re-reading what I wrote, I may have come across a bit negative. Quite the contrary!  This is still very much sounding like the Mainline in all cases just with a slight tilt a various directions.  The V-Caps arrive today. My friend has a Mainline with 10uf ODAMs. I’m getting the 15uf.

 

[Paul Birkeland]

Oh not to worry!  The 10uF caps included with the Mainline aren't particularly expensive and it's certainly worthwhile to experiment with other parts, though I agree that there are a lot of "audiophile" caps out there that aren't really to my liking.

 

[AllanMarcus]

I finally got around to changing the caps from the dayton 10uF to the same quality dayton 20uF. To my old ears, the 20uF caps sounds slight darker. I did give them 10-20 hour burn in (FWIW). I wouldn't say better; only different. I think I prefer the 10uF, but the difference was very subtle to me, and might just be poor audio-memory. I just don't understand how people can listen to something, make a change that takes minutes, then listen, then hear very subtle differences. I can barely hear suite differences with A/B testing.

Well, back to listening to music and neurotically curating my music collection.

 

[Phippers]

Hi everyone,

I've just ordered some capacitors to try a little capacitor rolling of the stock 10uF Dayton output caps in my Mainline and I was thinking about how to do A/B comparisons between different capacitors.

Reading back through this topic, I see than in the past people have proposed switching the capacitors in situ, with strong feedback advising against.

I was wondering what people actually ended up doing?  Any advice?

Call me crazy, but this was my thought:

• Take a mono source and connect it to both L & R inputs.
  
  Externally to the Mainline, connect the stereo headphone output and wire it to the A and B side of a toggle switch, take the common out to both the L & R sides of a headphone socket.
  
  Now using the external A/B switch, one could listen to either the Left side or the Right side of the Mainline.
  
  Compare L & R with the stock Daytons - satisfy oneself that they sound more or less the same.
  
  Swap out a capacitor on one side only..... then one has an instant A/B comparison between the two caps, with no nasty DC volts being switched.

Granted, it would only allow a Mono comparison, but I'm thinking that it would provide instant comparison of tonality / bass extension / any audible effect of changing the capacitor value.

Thoughts anyone?

 

[Paul Joppa]

It sounds very reasonable. My only caveat is that there will always be some differences between channels. They will usually be very subtle, but then so are the differences between good capacitors. For example, very small differences in level affect preferences even when they are not audible as level differences per se.

A good test might be to see what differences you hear with identical caps. Do you prefer the sound of one channel over that of the other? At the least, try swapping tubes to see if that channel preference changes. When comparing two different caps, you may need to swap caps and repeat the test so they get tested in each channel.

 

[Thermioniclife]

If I understand you correctly that seems like a reasonable solution. You could build an adaptor that plugs into the output jack, a short cable to the switch and a short cable to an external headphone jack. That way you don't have to make connections inside the amp other than change one cap. Pretty cheap to make, 1 stereo plug, 1 stereo jack, 1 spdt switch and and a box to mount them in.

 

[Paul Birkeland]

That is certainly an idea worth trying!

 

[Phippers]

Hi Paul,

> there will always be some differences between channels. They will usually be very subtle,

Yes - this was what I had in mind in step 4 : "Compare L & R with the stock Daytons - satisfy oneself that they sound more or less the same."

Of course there is an assumption being tested there   If they don't sound "more or less" the same, then that is another rabbit hole for exploration!

> very small differences in level ....

Yeah I was thinking about that after I posted. I might measure that. If they were significantly off then perhaps one would need to take steps to trim the levels (maybe at the source).


Hi Lee,

Yes, that's exactly the sort of thing I had in mind.


I did also think that one could sum the two outputs, but with one phase reversed, and directly monitor the difference signal. Of course, as Paul J points out there are other contributing differences in the channels and one would be listening to all of these differences, not just the differences between the caps.

I think that it might be a useful discovery technique though - for example, I would have thought that if there is any extra bottom end change when changing the cap value, then it would be readily discerned in the difference signal.

 

[Thermioniclife]

As far as summing and phase reversal on one channel is concerned I think you may be disappointed as you will get a null or cancelation of frequencies especially in the lower frequency range. I think your initial thought has merit and would be a good place to start. But having said that, empirical data is always needed to prove or disapprove theoretical solutions. Meaning as James Brown would say " It's your thing, do what you wanna do "

 

[Phippers]

Hi Lee,

Yes the cancellation is exactly the point.

If the two channels were perfectly identical, then the phase reverse & sum would result in a perfect null - i.e. silence at all frequencies.

Then, if a change in one channel is supposed to (say) extend the bass response, then one would expect to hear just that blob of extra bass in the difference signal.

Not something nice to listen to, but a diagnostic tool. 

Of course in the real world things are far from perfect, but if that (say) extended bass response was significant, I would expect to be able to hear it in the difference signal.

It is a technique that I have used in the past when eq-ing or otherwise treating a mix - for example, applying a de-noise algorithm. It can be all too easy to focus on the one parameter one is adjusting, to go too far and totally miss the havoc that one is wreaking somewhere else in the mix.

The phase reverse trick can be very revealing of what else is going on, unwanted artifacts and suchlike. Once you can isolate the artifacts and learn what they sound like, they are easier to spot in a dodgy mix.

But I digress!  I was just thinking aloud that it might be worth a go here too - was just an idle thought. Easy enough to try.

 

[Doc B]

You could just run a response curve of each channel and compare. It's going to be very subtle.

 

[Phippers]

Hi Doc,

Yep I'll probably do that as well.

 

[amirhosein]

Thanks for the response PB!  I wanted to put down some listening notes while it was still fresh in my head, sorry for the long post. In re-reading what I wrote, I may have come across a bit negative. Quite the contrary!  This is still very much sounding like the Mainline in all cases just with a slight tilt a various directions.  The V-Caps arrive today. My friend has a Mainline with 10uf ODAMs. I’m getting the 15uf.

Sorry to dig up an old post, but would you mind sharing your impressions using the V-Caps if any?