[itsikhefez]

Well, for low-impedance headphones, Mainline is the only option between the two, but for 300 ohm + headphones such as the Sennheisers, I think that Crack just stands on it's own in terms of good interesting OTL sound.

I think Crack was the first tube amp I felt worthwhile being a tube amp as it's so engaging with the Sennheiser HD6 series. Mainline just isn't the same experience.

If you get a chance, give it a listen. There's a reason why Crack is so famous. It's a fast sounding with good imaging for HD6 series Sennheisers.

If you are going for a budget tube, I'd recommend Crack as the best introduction.

Thanks for the insight. I know inside that at some point I'll have to build it even though my amp collection is growing and its really unnecessary.
I have an Elekit TU-8600 300B tube amp kit coming in tomorrow. This is intended for a speaker system but it should be great with headphones as well... it will be a good comparison to the Mainline in terms of "tube sound"

 

[SilverEars]

Thanks for the insight. I know inside that at some point I'll have to build it even though my amp collection is growing and its really unnecessary.
I have an Elekit TU-8600 300B tube amp kit coming in tomorrow. This is intended for a speaker system but it should be great with headphones as well... it will be a good comparison to the Mainline in terms of "tube sound"

That's a high powered one? Would be interesting to try planars with it. Curious if it powers HE-6 well enough.

 

[itsikhefez]

That's a high powered one? Would be interesting to try planars with it. Curious if it powers HE-6 well enough.

Yes, as a 300B SET amp it outputs 8W.. not sure how much goes to the headphone output but I believe it should be very powerful

 

[JamieMcC]

Here's my opinion on the Mainline vs Crack. Get the crack, forget about the Mainline, and save the money (you have to use 300 ohm+ headphones though). Mainline is overpriced for performance. For that kind of performance, I'd go shoot for a good solid-state instead. It's a tube amp fails at trying to be a good solide-state which kinda defeats being a tube amp.

After listening to Crack with speedball, you'd think Mainline would be a refined Crack. Nope. It's just a different sounding tube amp that happens to be very expensive.

Compared to Crack, you lose the high separation and the interesting imaging. Mainline sounds a bit smeared in definition and has the that caveat of tube sound that compares badly to a good solid-state.

Mainline just proves a point that just because one amp sound good doesn't mean their higher-end is worth the upgrade, or should you expect to be. Somehow Crack happens to be a good sounding amp. Luck maybe?

Was the Crack modified in any way what tubes were you using?

 

[SilverEars]

Was the Crack modified in any way what tubes were you using?

No modification. I actually tried two Cracks (both stock) with Speedball and liked the non-warm and lush, with strong bass of HD6 series out of both of them. I finished a Speedball build for somwbody, and discovered it was my kind of soubd out of the Sennheisers. I immediately looked for a Crack of my own after hearing the Speedball.

I fed it Gumby. I guess OTL works well with Gumby. I tried out another amp that's transformer coupled, and it can sound a bit warm with the wrong DAC, was a bit sensitive and sounded more precise out of a dry DAC. I don't like warm sounding, particularly with HD6XX.

 

[JamieMcC]

No modification. I actually tried two Cracks (both stock) with Speedball and liked the non-warm and lush, with strong bass of HD6 series out of both of them. I finished a Speedball build for somwbody, and discovered it was my kind of soubd out of the Sennheisers. I immediately looked for a Crack of my own after hearing the Speedball.

I fed it Gumby. I guess OTL works well with Gumby. I tried out another amp that's transformer coupled, and it can sound a bit warm with the wrong DAC, was a bit sensitive and sounded more precise out of a dry DAC. I don't like warm sounding, particularly with HD6XX.

So you were using hd6xx with Mainline as well then?

 

[SilverEars]

So you were using hd6xx with Mainline as well then?

600/6XX

 

[JamieMcC]

600/6XX

Try having a read through the reviews on the very first page of this thread by Loquah the thread creator and his comparisons of Crack, Sex and Mainline after. Having owned all three myself (still have Sex and Mainline) and also been able to compare side by side a stock Crack and maxed out hot rodded Crack premium tubes etc. I think Loquah assessment of the differences is pretty accurate.

I've owned the hd600 and hd650 in the past at a guess I would suggest both the Grumby and Mainline performance are being restricted by the ability of your cans.
The Mainline is capable of resolving details your not even going to know exist on the hd650 Crack combo and that's with you knowing they are there and listening for them.

Like I say have a look over Loquah's comparisons, the Crack hdxxx is a fantastic combo but to my mind the Sex and Mainline do seriously ratchet up the performance in comparison something that much more easily noticed with cans like the T1 and HD800. I think headfiers are pretty lucky at the moment there seems a real push from manufacturers upping their game and the level of performance from the more budget friendly end of the market is continuously improving snapping at the heels of more premium offerings.

 

[attmci]

HD-650 is a fine headphone which I still use to test new tubes. However, the cable comes with it is so cheap. I replaced it with a Silver Dragon (not very expensive).

 

[NightFlight]

Try having a read through the reviews on the very first page of this thread by Loquah the thread creator and his comparisons of Crack, Sex and Mainline after. Having owned all three myself (still have Sex and Mainline) and also been able to compare side by side a stock Crack and maxed out hot rodded Crack premium tubes etc. I think Loquah assessment of the differences is pretty accurate.

I've owned the hd600 and hd650 in the past at a guess I would suggest both the Grumby and Mainline performance are being restricted by the ability of your cans.
The Mainline is capable of resolving details your not even going to know exist on the hd650 Crack combo and that's with you knowing they are there and listening for them.

Like I say have a look over Loquah's comparisons, the Crack hdxxx is a fantastic combo but to my mind the Sex and Mainline do seriously ratchet up the performance in comparison something that much more easily noticed with cans like the T1 and HD800. I think headfiers are pretty lucky at the moment there seems a real push from manufacturers upping their game and the level of performance from the more budget friendly end of the market is continuously improving snapping at the heels of more premium offerings.

You can go further and say that the HD800 starts to fail at presenting air and realism of stringed instruments, etc when compared to a top tier electrostatics and the requisite chain to make them perform. What it comes down to is, how much money do you want to drop for crazy realism, vs some simple fun.

But I agree. The "don't waste your money on a Mainline" mantra is to be expected coming from a HD6xx only standpoint. Given I have the 600/650 and 800, I relegate the 600 to workhorse duty for movies and such. The 650 to nightstand duty (movies/music) and the HD800 for my main rig. The 600 vs 800 series are totally different animals. Going back to the 650 from 800 in the same session is like loosing a good chunk of your perception. The 650's are great, but the 800's are that much better.

 

[L0rdGwyn]

Pretty sure I am the only person on HF actually rolling these tubes, but in case anyone is interested, attained the "end game" of shunt regulator tubes for the Crackatwoa, Telefunken 6005, took quite a while to find a pair.

 

[Tom-s]

Nice! If those are Tele's they must have a date code on the back starting with U. The ribbed plate 6AQ5W like yours (6005) were made in Ulm (38.270pcs, based on GE 6005). In the Berlin factory they made the smooth plate 6aq5/EL90's version (545.416pcs, more like RCA 6aq5's). I only have the Berlin made Tfk EL90's in my collection for now (and lots of RCA from all over the world and 6005 GE's that have the same internal construction like the ones you show above).

Could you provide some close-ups of the internals? Or compare them to GE 6005/6aq5w?

 

[L0rdGwyn]

Nice! If those are Tele's they must have a date code on the back starting with U. The ribbed plate 6AQ5W like yours (6005) were made in Ulm (38.270pcs, based on GE 6005). In the Berlin factory they made the smooth plate 6aq5/EL90's version (545.416pcs, more like RCA 6aq5's). I only have the Berlin made Tfk EL90's in my collection for now (and lots of RCA from all over the world and 6005 GE's that have the same internal construction like the ones you show above).

Could you provide some close-ups of the internals? Or compare them to GE 6005/6aq5w?

Hey Tom - I'd be happy to! I own the smooth plate, Berlin-made Telefunken EL90s as well. Below are are some pics of the internals, as well as a pic of the GE 6005 internals. The Ulm designation is not included in the date code, but is indicated on the box. As far as how the internals compare to the GE's, you can see the getter is raised and parallel to the top mica, unlike the GE's. This is not pictured, but on the GE's, the cylindrical plates are sectioned in two places, like two half circles meeting, whereas on the Tele's, is is a single sheet that meets in one place. The plates of the Tele's also have a bit more luster.



Here is a GE 6005:

 

[SmashBruh]

Since my ZMF pendant doesn't seem to be working out I'm thinking about upgrading the caps in my mainline. I didn't build the mainline myself and am a little nervous about swapping out the parts but I'm hoping it's relatively painless! (Any tips any of you may have would be greatly appreciated though.)

I do have a question in regards to what capacitors I should choose though-

First of all, is it necessary to put in a capacitor that fits exactly where the old Daytons were? I'm thinking about going with either the Auricap 18uf or a Mundorf Supreme Silver Gold Oil. The latter will never fit where the old Daytons were, so I was wondering if it would be okay to just have them be suspended there? (Any tips on how best to suspend them would be helpful too!)

Also, is there any actual benefit to having a higher UF rated cap? The Auricap I'd get is 18 uf but the biggest permissable uf for the MSSGO that I've found was 15. Does that mean the Auricaps are a better choice? Or does it not matter and would a 10uf MSSGO sound just as good as its 15uf counterpart? (it's a $400 difference lmao)

Also, I'm having a tough time deciding between capacitors. I really love the stock tonality of the mainline. It sounds "right" and I really wish to keep that, however I wish the treble was a little more energetic and I also wish it slammed harder. Based off of that would you say the Mundorf is the better choice of capacitor or would either one do? (The auricaps are undoubtedly cheaper so I'd rather go for them, but I've been reading great things about the Mundorfs.)
Another question I have regarding the mundorfs- did those of you who switched to them ever feel you recovered the "sense of space" you lost after they burned in?? The imaging on my mainline is one of my favorite parts of it! Another worry I have is that if this is really only a marginal upgrade no matter what maybe going for something like the MSSGO might be wasting money?

 

[itsikhefez]

Since my ZMF pendant doesn't seem to be working out I'm thinking about upgrading the caps in my mainline. I didn't build the mainline myself and am a little nervous about swapping out the parts but I'm hoping it's relatively painless! (Any tips any of you may have would be greatly appreciated though.)

I do have a question in regards to what capacitors I should choose though-

First of all, is it necessary to put in a capacitor that fits exactly where the old Daytons were? I'm thinking about going with either the Auricap 18uf or a Mundorf Supreme Silver Gold Oil. The latter will never fit where the old Daytons were, so I was wondering if it would be okay to just have them be suspended there? (Any tips on how best to suspend them would be helpful too!)

Also, is there any actual benefit to having a higher UF rated cap? The Auricap I'd get is 18 uf but the biggest permissable uf for the MSSGO that I've found was 15. Does that mean the Auricaps are a better choice? Or does it not matter and would a 10uf MSSGO sound just as good as its 15uf counterpart? (it's a $400 difference lmao)

Also, I'm having a tough time deciding between capacitors. I really love the stock tonality of the mainline. It sounds "right" and I really wish to keep that, however I wish the treble was a little more energetic and I also wish it slammed harder. Based off of that would you say the Mundorf is the better choice of capacitor or would either one do? (The auricaps are undoubtedly cheaper so I'd rather go for them, but I've been reading great things about the Mundorfs.)
Another question I have regarding the mundorfs- did those of you who switched to them ever feel you recovered the "sense of space" you lost after they burned in?? The imaging on my mainline is one of my favorite parts of it!

I can partially comment here, hopefully others will chime in as well (also, I'm by no means an expert so take with a grain of salt).
Those caps should be relatively easy to swap out, assuming you have some soldering experience.
I would not recommend having the caps suspend there, as it would put mechanical stress on the leads and thats probably a bad thing in the long run.
I used the Auricap XO in mine and put a piece of double-sided tape mount them to the chassis. You could also use a wire routing hook with zip ties.

In terms of size, there is a minimum capacitance needed in a given circuit to avoid frequency roll off. I'm not sure what that is in the Mainline. Personally, I would probably use the stock value or slightly higher.

Regarding the cap type, I'm personally in constant question on this topic. On the one hand, there are alot of boutique ($$$) caps that are highly rated subjectively, but on the other hand most people with actual engineering experience brush it all off and say its snake oil. I also think that the differences people mention between caps is pretty exaggerated.
As long as the materials and technology are the same (i.e, metallized polypropylene, film and foil, paper in oil), the differences are probably going to be subtle.