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The Little Dot Mk IV / SE Impressions Thread - Page 32

post #466 of 551
Quote:
Originally Posted by hypnos1 View Post
 

 

And not only that, but at the risk of repeating myself, I can say that without doubt these 6AS7Gs are giving me a taste of hi-end at a lo-to-mid-end price. NOTHING could have prepared me for the difference they are making. Now my new adapter is well run-in, along with all the other goodies I have described (many times!) the depth of bass (as blew me away on revisiting Dire Straits' track 'Love over Gold') is now as never before...together with its wonderful detail...sheer bliss!

Can't wait to see what happens when silver wire adapter #2 gets finished, lol!

"I can say that without doubt these 6AS7Gs are giving me a taste of hi-end at a lo-to-mid-end price."

 

Well I probably won't be making mods for quite a while after I get to hear other systems and I'm convinced it would be worth it. But what you are saying about high-end at nearly low-end prices is sounding good should I think it worth it. I probably won't hear the other systems I would like to hear until a headphone show in early October. So I am certainly considering modifying my IV SE amp on what must be considered a very long-term basis.

 

Consequently since I find that rolling thread hard to follow since the information there is very spread out among many pages I would appreciate it if when you are all through you could post say on this thread a consolidated guide for dummies that might be easier to follow.

 

So far I am gathering the big power tubes you are using need a beefier heater current supply there are no pictures on that rolling thread showing how you wire in the beefier power supply. It also seemed like you were suggesting some resistors have to be changed to higher wattage, but then may have changed your mind.

 

So it won't be for quite a while when I may wish to embark on doing mods, but will certainly very much appreciate it if when you feel you have come close to finishing your little dot IV SE mods you would post some sort of guide for dummies.

 

PS I used to be electronic technician so I probably have adequate screwdriver and soldering ability.

post #467 of 551

the C3G Mod is easy, but costly in the end.

 

http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665

post #468 of 551
Quote:
Originally Posted by bbmiller View Post
 

"I can say that without doubt these 6AS7Gs are giving me a taste of hi-end at a lo-to-mid-end price."

 

Well I probably won't be making mods for quite a while after I get to hear other systems and I'm convinced it would be worth it. But what you are saying about high-end at nearly low-end prices is sounding good should I think it worth it. I probably won't hear the other systems I would like to hear until a headphone show in early October. So I am certainly considering modifying my IV SE amp on what must be considered a very long-term basis.

 

Consequently since I find that rolling thread hard to follow since the information there is very spread out among many pages I would appreciate it if when you are all through you could post say on this thread a consolidated guide for dummies that might be easier to follow.

 

So far I am gathering the big power tubes you are using need a beefier heater current supply there are no pictures on that rolling thread showing how you wire in the beefier power supply. It also seemed like you were suggesting some resistors have to be changed to higher wattage, but then may have changed your mind.

 

So it won't be for quite a while when I may wish to embark on doing mods, but will certainly very much appreciate it if when you feel you have come close to finishing your little dot IV SE mods you would post some sort of guide for dummies.

 

PS I used to be electronic technician so I probably have adequate screwdriver and soldering ability.

Look on page 300 post #4493 to #4495, 301, and 326 of the tube rolling guide thread it gives you a good idea of what to do and what you need .Here are a few of the adapters i made.   Got questions let me know. Since you have the LD 4 if you use these adapters like these you will have to remove the brass tube protectors Got questions let me know.                                                                                                                                                                               Heres a list of tubes compatible with the adapters       http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3990#post_9983735

                                                                                                                                                                                                     

 

 

 


Edited by MIKELAP - 5/19/14 at 4:16pm
post #469 of 551
Quote:
Originally Posted by bbmiller View Post
 

"I can say that without doubt these 6AS7Gs are giving me a taste of hi-end at a lo-to-mid-end price."

 

Well I probably won't be making mods for quite a while after I get to hear other systems and I'm convinced it would be worth it. But what you are saying about high-end at nearly low-end prices is sounding good should I think it worth it. I probably won't hear the other systems I would like to hear until a headphone show in early October. So I am certainly considering modifying my IV SE amp on what must be considered a very long-term basis.

 

Consequently since I find that rolling thread hard to follow since the information there is very spread out among many pages I would appreciate it if when you are all through you could post say on this thread a consolidated guide for dummies that might be easier to follow.

 

So far I am gathering the big power tubes you are using need a beefier heater current supply there are no pictures on that rolling thread showing how you wire in the beefier power supply. It also seemed like you were suggesting some resistors have to be changed to higher wattage, but then may have changed your mind.

 

So it won't be for quite a while when I may wish to embark on doing mods, but will certainly very much appreciate it if when you feel you have come close to finishing your little dot IV SE mods you would post some sort of guide for dummies.

 

PS I used to be electronic technician so I probably have adequate screwdriver and soldering ability.

 

Hi bbmiller...and to whomsoever else it may concern...

 

Glad you found my 'massive missive' interesting, even if I may have put you also into overload mode! -  no wonder, as this is the culmination of a year's worth of loooong slog (but worth every mind-scrambling second, lol!)...which brings me to a rather down-to-earth (not with a bang, I trust) statement...

Being brutally honest, much as I would gladly (try to) cobble together a consolidated guide, I'm afraid there is no quick, easy way to go the "full" DIY route to nirvana...one would need to be really really keen; be prepared to wade through many, many pages of the rolling thread; be fully confident with things like pin layouts/routing etc., and have a good deal of time (and patience!)...buckets of it, in fact!.

 

So in all honesty, I do not actually recommend this course of action. Better by far would be to save up your pennies/dollars and go the route I mentioned previously - using bought adapters...a bit costly yes, but MUCH MUCH easier - and safer.

 

As for the mods needed re power supply to the 6AS7G tubes, I shall post later some photos of how I did it...this will not need anywhere near the in-depth slog I just mentioned - especially with your tech abilities.

 

And re the tubes themselves, a wonderful source (thanks gibosi - one of the 'avatars' on our rolling thread) is vacuumtubes.net (not.com). They have a good selection at very good prices - RCAs at $15 (which I have, and are excellent), and Chathams at $20 ea (which I shall be trying - supposed to be a bit better, but time will tell)...the RCAs, though, are very well respected, it appears.

 

Ah well, dinner time, so I shall have to say cheerio for now...but I'll be back!


Edited by hypnos1 - 5/20/14 at 12:55pm
post #470 of 551
Quote:
Originally Posted by Chris J View Post


Well.......honestly, I am in "overload mode".
Give me a few millennia to digest this.....confused_face_2.gif

Edit:
You don't have to worry about the envelope temperature of the 6AS7, but you may want to check the case temperature of your Little Dot.

 

Hi Chris J.

 

Checked the case temp. and read 36C after 1 hour and just 39C after 4.5 hrs. Nothing too drastic, eh? Hopefully the MKIV SE has displayed its amazing, forgiving versatility once again...:bigsmile_face:.

 

Quote:
Originally Posted by bbmiller View Post
 

"I can say that without doubt these 6AS7Gs are giving me a taste of hi-end at a lo-to-mid-end price."

 

Well I probably won't be making mods for quite a while after I get to hear other systems and I'm convinced it would be worth it. But what you are saying about high-end at nearly low-end prices is sounding good should I think it worth it. I probably won't hear the other systems I would like to hear until a headphone show in early October. So I am certainly considering modifying my IV SE amp on what must be considered a very long-term basis.

 

Consequently since I find that rolling thread hard to follow since the information there is very spread out among many pages I would appreciate it if when you are all through you could post say on this thread a consolidated guide for dummies that might be easier to follow.

 

So far I am gathering the big power tubes you are using need a beefier heater current supply there are no pictures on that rolling thread showing how you wire in the beefier power supply. It also seemed like you were suggesting some resistors have to be changed to higher wattage, but then may have changed your mind.

 

So it won't be for quite a while when I may wish to embark on doing mods, but will certainly very much appreciate it if when you feel you have come close to finishing your little dot IV SE mods you would post some sort of guide for dummies.

 

PS I used to be electronic technician so I probably have adequate screwdriver and soldering ability.

 

Hi bb.

 

As promised, here's a couple of photos of the set-up - the laptop supply and the voltage regulator are usually tucked away underneath, on a lower shelf of my equipment stand...:

 

 

 

The laptop power supply connector is crudely patched to the regulator...didn't want to cut the cable - still need it for the laptop! Am getting a similar supply (but aimed at powering led string lights - 12V/6A) from Amazon for just £11...the tubes need a total of 5A for the heaters.

This particular voltage regulator - $8.99 from Amazon, and rated for 8A - is not very solidly made (I managed to dislodge the solder connections on the output block just by tightening the screws!... but easily resoldered). It also does not have a readout, so a meter is needed to get to the required 6.3V - rough measurement first at the regulator before connecting tubes, then final check at the pins ...some have found a slight difference. This regulator is adjusted by a small screw atop a blue block (can just be seen on the far side of the pic). I was going to splash out on a bench DC power supply, but that was "damaged in transit" - supposedly! - so I am saving myself some money and have gone for another  DC 'buck' regulator, but this time a beefier one (12A) with more protection circuits, and even with the new power supply still a lot cheaper than the 'bench'.

 

Re the heater pins (#s 4&5) of the 6SN7 to 6CG7 adapter (available on ebay, but there are more going the other way ie 6CG7 to 6SN7, so beware!)  as can be seen, they have been cut leaving just enough to solder the wires from the regulator. Here I have covered them with white 'blu-tak', a form of plasticine, but good insulating tape would actually be better methinks...it would also be a good idea to insulate at the socket, just to be sure...you do NOT want those pins connecting to the LDs supply,lol!! With as little protrusion as possible, the adapter should seat OK in the socket.

 

Hopefully this is clear enough, but please ask any questions if unsure about anything...

 

ps. Sorry if I'm stating the obvious, but when numbering the pins, look from below (as shown in the photo) and with these '9-pins' the larger gap denotes the 1-9 position - #1 is to the left as you look, and they run clockwise.

 

Quote:
Originally Posted by superdux View Post
 

the C3G Mod is easy, but costly in the end.

 

http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665

 

At least with our MKIVs we don't (thankfully!) have to worry about the extra extender/tester adapter...we just have to remove ALL of the 'brass' bits (plate included) and the adapters fit OK :D.

 

I'm actually going to see what happens with the straight-replacement 6HM5 in place of the C3g...should be very interesting to see what they can deliver, with the 6AS7G in the hot seat. Will keep you all posted.

post #471 of 551
Quote:
Originally Posted by hypnos1 View Post
 
 

 

 

 

Well I may have more questions later, but one occurs to me right now. The way you seem to be doing it the heat a power supply is just feeding the heater through the adapter. I'm assuming the plate voltage is still coming from the internals of the little dot IV amp if that is the case with their be any need to create a common ground between your power supply and the one in the amp?

post #472 of 551
Quote:
Originally Posted by bbmiller View Post
 

Well I may have more questions later, but one occurs to me right now. The way you seem to be doing it the heat a power supply is just feeding the heater through the adapter. I'm assuming the plate voltage is still coming from the internals of the little dot IV amp if that is the case with their be any need to create a common ground between your power supply and the one in the amp?


Hi bb.

 

Yes indeed, the external power supply is feeding just the heaters. And mine is totally separate from the LD's supply...no common ground...and no hum!

 

Cheers.

 

Edit...ps. Did not change the resistors - the transformer would probably blow instead!!


Edited by hypnos1 - 5/22/14 at 5:37am
post #473 of 551

Hi guys.

 

As promised, here's the preliminary result of replacing the C3GS with the (MUCH) cheaper, straight replacement tall-bottle 6HM5....all I can say is I'm gobsmacked!

 

I never expected such a result...not all that far off the C3Gs, in fact...and am still in shock, lol! They never sounded anything like this, even with the mightily expensive 6N30P-DRs.

 

This is final proof that the old-established "wisdom" re the power tubes only having a slight influence on the final results is now totally WRONG ! These 6AS7Gs have rewritten the book...they are absolutely amazing. Will next try the Tesla E88CC (with gold grids & pins but need to be adapted)...these were far better in the old set-up, so it should be interesting to see how they perform driving the 6AS7Gs...this rolling game just keeps throwing up surprise after surprise - certainly with our humble LDs, anyway!

 

 

A touch of David and Goliath?!

post #474 of 551


As an update (belated!) to my previous thread, although the Tesla E88CCs performed better than the 6HM5s, they were no match for the C3GSs - these truly are in another league...

 

I also put in some Chatham 6AS7Gs in place of the RCAs, and the sound went up yet another notch...absolutely fabulous! I am finally (?!) 100% sure I have pushed the MKIV SE to its absolute limits (without spending silly money, that is) - WAY beyond the stock offering, lol. I can only hope other MKIV owners can experience this rather amazing result...borne of a year's worth of joining in the rolling thread, and sharing the wonderful work that has been going on there...and still IS!

 

Whatever, ENJOY your marvellous value-for-money machine...

post #475 of 551
Hi all
Quick inquiry how is the little dot mkiv se and HE-400 and or HE-500?
Thanks
post #476 of 551

Setting up a headphone rig at home. I have a high-end rig at work (see sig). 

 

Just wondering, what is the best headphone to pair with the Little Dot MK IV? I didn't find the HD650 that great with the Little Dot, but that's more because I don't think much of the HD650.

 

Has anyone tried pairing it with a closed headphone like the TH900? 

 

I enjoy the Little Dot with the K701 much more than the HD800 but both sound bright driven by the Little Dot.

 

Thanks!

post #477 of 551
Quote:
Originally Posted by Kozic View Post

Hi all
Quick inquiry how is the little dot mkiv se and HE-400 and or HE-500?
Thanks

 

Quote:
Originally Posted by lojay View Post
 

Setting up a headphone rig at home. I have a high-end rig at work (see sig). 

 

Just wondering, what is the best headphone to pair with the Little Dot MK IV? I didn't find the HD650 that great with the Little Dot, but that's more because I don't think much of the HD650.

 

Has anyone tried pairing it with a closed headphone like the TH900? 

 

I enjoy the Little Dot with the K701 much more than the HD800 but both sound bright driven by the Little Dot.

 

Thanks!

 

I run the LD MK IV with beyerdynamics DT880 Pro's @ 250Ω which pairs very nicely depending on the tubes you use.

The OTL line of Little Dot amplifiers MK II, III, IV(SE) don't mesh well with lower impedance headphones in my experience, since they are all designed to optimally run higher impedance headphones. I get a hum with my Ultrasones on the MK IV.

 

One possible solution might be to look into a transformer coupled amplifier for the low Z headphones such as the Woo WA6 which comes highly recommended around here.

post #478 of 551
Th
Quote:
Originally Posted by TrollDragon View Post


I run the LD MK IV with beyerdynamics DT880 Pro's @ 250Ω which pairs very nicely depending on the tubes you use.
The OTL line of Little Dot amplifiers MK II, III, IV(SE) don't mesh well with lower impedance headphones in my experience, since they are all designed to optimally run higher impedance headphones. I get a hum with my Ultrasones on the MK IV.

One possible solution might be to look into a transformer coupled amplifier for the low Z headphones such as the Woo WA6 which comes highly recommended around here.

Thanks. Anyone had any luck driving planars with the LD mkIV? I'm thinking of the Alpha Dog.
post #479 of 551
Quote:
Originally Posted by lojay View Post

Th
Thanks. Anyone had any luck driving planars with the LD mkIV? I'm thinking of the Alpha Dog.


Well they drive my LCD2 but saying that I have to say they sound a lot better on my Lyr.

post #480 of 551

What are the best tube combos for the LD Mk IV and Beyer DT880 (250 Ohms)? I presume a warmer / bassier combo would be best?

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