[cswann1]

(Mods, if this is in the wrong place, please let me know)

LDMKIV tube rolling question from a newbie.

Bought my first tube to roll with: a pair of Mesa Boogie EL84/6BQ5s, recommended by a local dealer. They aren't working right: there's hardly any sound, just horrible static.

They are seated correctly, and I have de-oxidised the pins. They do not appear to be damaged or dead (silver top, no purple glow etc), and I bought them from a reputable dealer. Stock tubes working fine, with good sound, so it's not the amp itself. Before I send them back: it occurs to me that I may need to change the jumper switches. But I don't know what these look like, and Google is no help. Neither unfortunately is the LD manual/reference guide.

Do I need to change the jumper switches? If so, where are they? And please don't say 'next to the capacitors' - assume I'm an idiot please! Muchas gracias

As far as I have been able to determine the EL84 valve is not a drop in replacement for the LD MKIV.

Here is a link to the owners manual that gives some info on tube rolling, however the power tubes don't include jumper settings for alternate tube types.

https://www.dropbox.com/s/biytahabdg1xs1c/Little Dot MK IV SE Reference Guide.pdf?dl=0

I would stick with the power tubes that shipped with your amp. If you want to experiment with different flavors of sound, its the driver tubes you want to roll. They have far more effect on the sound.

 

[Acapella11]

(Mods, if this is in the wrong place, please let me know)

LDMKIV tube rolling question from a newbie.

Bought my first tube to roll with: a pair of Mesa Boogie EL84/6BQ5s, recommended by a local dealer. They aren't working right: there's hardly any sound, just horrible static.

They are seated correctly, and I have de-oxidised the pins. They do not appear to be damaged or dead (silver top, no purple glow etc), and I bought them from a reputable dealer. Stock tubes working fine, with good sound, so it's not the amp itself. Before I send them back: it occurs to me that I may need to change the jumper switches. But I don't know what these look like, and Google is no help. Neither unfortunately is the LD manual/reference guide.

Do I need to change the jumper switches? If so, where are they? And please don't say 'next to the capacitors' - assume I'm an idiot please! Muchas gracias

Hi, check this post for tube alternatives. I suggest to post your question in this forum as well:
https://www.head-fi.org/threads/lit...e-rolling-guide.563884/page-585#post-11155053

 

[robboffard]

Hi, check this post for tube alternatives. I suggest to post your question in this forum as well:
https://www.head-fi.org/threads/lit...e-rolling-guide.563884/page-585#post-11155053

As far as I have been able to determine the EL84 valve is not a drop in replacement for the LD MKIV.

Here is a link to the owners manual that gives some info on tube rolling, however the power tubes don't include jumper settings for alternate tube types.

https://www.dropbox.com/s/biytahabdg1xs1c/Little Dot MK IV SE Reference Guide.pdf?dl=0

I would stick with the power tubes that shipped with your amp. If you want to experiment with different flavors of sound, its the driver tubes you want to roll. They have far more effect on the sound.

Cool, thank you!

 

[robboffard]

Hi, check this post for tube alternatives. I suggest to post your question in this forum as well:
https://www.head-fi.org/threads/lit...e-rolling-guide.563884/page-585#post-11155053

Will do, thanks!

 

[MIKELAP]

YOU CANNOT USE THIS TUBE IN YOUR AMP heater current is .760 ma MAX/per channel is .500ma look on page 77 for the tubes you can try

 

[White Lotus]

Some photos:

 

[cswann1]

Very nice pics!

 

[bugeyed]

Just tried to listen to my LD MKIV SE with the HE-400i & it was a fail. Tracks was Holly Cole Train song. Some serious upright bass & that's where the LD failed. Even a moderate levels the bass was not tight at all. It had a flabby sound on the verge of break up. Un-listenable. Tried the HD650 & they worked fine. Guess it's an impedance thing, I think the 400i is 35 Ohm? May just be too low for the LD to control the bass. I understand about damping factor & impedance mismatch, but have never actually experienced it. I will experimant more in the next few days. I have another pair of HP with Z of 250 Ohms. Otherwise I love this amp.
Kev

 

[sennsay]

Just tried to listen to my LD MKIV SE with the HE-400i & it was a fail. Tracks was Holly Cole Train song. Some serious upright bass & that's where the LD failed. Even a moderate levels the bass was not tight at all. It had a flabby sound on the verge of break up. Un-listenable. Tried the HD650 & they worked fine. Guess it's an impedance thing, I think the 400i is 35 Ohm? May just be too low for the LD to control the bass. I understand about damping factor & impedance mismatch, but have never actually experienced it. I will experimant more in the next few days. I have another pair of HP with Z of 250 Ohms. Otherwise I love this amp.
Kev

Yes, interesting, isn't it. I certainly didn't enjoy the HE400S with my upgraded Valhalla 2 (since sold), they are much improved with the Mimby/Magni 3 combo, if not as brilliant as my 600 ohm HD540 Ref1s! After over 18 months with the HE400S, I still prefer them straight out of the Questyle QP1R - with either stock or hand-made cable - where they are very good indeed. Even with only 40mW of pure Class A on hand! The only thing I really don't like about them is that lower treble peak which tends to blend vocals with the harmonics of other instruments, leading to voices not separating forward from them as happens with my other headphones. It's better with the newer cable, but still a feature of these cans. Now, if they could just flatten out that peak .......

 

[TrollDragon]

OTL amplifiers like the Little Dot MK IV require high Z headphones to shine, the amplifier was not designed for 35Ω cans.

 

[wwmhf]

OTL amplifiers like the Little Dot MK IV require high Z headphones to shine, the amplifier was not designed for 35Ω cans.

Totally agree. This is one of the thing you do not need to "even try"

 

[HollowNoise]

Hey peeps, any ideas on how the LD MK IV/SE perform compared to the Bottlehead Crack? Anyone heard the two? Also MK IV with C3g tubes vs stock Bottlehead with Speedball?

 

[evolutiontheory]

Sorry for the tangent..
Is there a similar thread for LD MK2? I had some doubts, but unable to find the forum

 

[adbar86]

Hi all, I'm new here Just have a quick question... I own LDIVse the very first version and wondering if you can advise me any best value/money power tubes with adapters or without. And what about 6N6P it will work with the earlier version of IVse?
My LD came with the power valves visible on the picture any idea what they are? The name rubbed off

 

[sennsay]

Hi all, I'm new here Just have a quick question... I own LDIVse the very first version and wondering if you can advise me any best value/money power tubes with adapters or without. And what about 6N6P it will work with the earlier version of IVse?
My LD came with the power valves visible on the picture any idea what they are? The name rubbed off

Hi adbar86, I don't own a LDIV - although I think I'd like to some time - however, something that might be of interest to you is that on the LampizatOr site, he quotes the 6H6P (notice I didn't say 6N6P!) as THE valve/tube to use and that they were used on the LD models - or at least some of them - I think from LDII to LDIV. They perform much better, are supremely linear, take less power to drive them, can run at lower voltages and sound magnificent. I'm paraphrasing his words, but he is the dude for using these tubes, I mention this because it is THE tube to use for converting my Zero DAC to tube output, rated very highly as such and that I would like to do! As a newbie here, you probably won't want to just pop the lid and see how the output tubes are wired for the heaters, but here is the link to the 6H6P Club site, it's worth reading. All the best with it.
http://www.lampizator.eu/UPGRADE/upgrade noval tubes to 6H6P.html