[john57]

It seems that there is allot of RF pollution in the home environment as people move away from wired connections. Any audio device close to a transmitter can cause interference. I did had some issues with cables picking up RF signals cause a sort of overload that spilled into the audio range of the device. I use ferrite cokes on the cables and correct placement of wireless devices can do much to reduce interference. In the old tube TVs there were metal shields on some tubes to protect them from other tubes and the strong magnetic fields on the main picture tube that can generate interference with some tubes. Driver tubes or the pre-amp tubes are more likely to pick up interference than power tubes because of the gain factor.

 

[cruizin caleb]

Quote:

You might want to check out the Amperex 6AK5W for a tube with a strong low end.  They were not easy for me to find, but they are still out there.  A nice combo with the 2107 for good bass and a warm sound.
 

http://cgi.ebay.com/2x-Amperex-EF91-Matched-Pair-Little-Dot-Amp-Mk-III-6AM6-/290582170623?pt=Vintage_Electronics_R2&hash=item43a80c0bff#ht_1234wt_1141
 
are these the bass heavy Amperex tubes people have been talking about in this thread? it doesn't say 6ak5w but isn't that the same as EF91? i'm confused.
 

 

[shipsupt]

http://cgi.ebay.com/2x-Amperex-EF91-Matched-Pair-Little-Dot-Amp-Mk-III-6AM6-/290582170623?pt=Vintage_Electronics_R2&hash=item43a80c0bff#ht_1234wt_1141
 
are these the bass heavy Amperex tubes people have been talking about in this thread? it doesn't say 6ak5w but isn't that the same as EF91? i'm confused.
 

The 6AK5 equivalent is the EF95, the 6AK5W is the EF95F, so no these aren't the tubes frequently mentioned.

 

[zero7525]

 
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I just got my Little Dot 1+ a week ago. To summarize my thoughts so far, I believe that the highs in my DT880 32 ohm became more refined, the bass tighter and less loose, and the mids more lush and forward than without an amp. Switching between the stock 6JI and the WE408A tubes, I believe that the stock ones put out a lot more bass and the highs were unrefined, a dark/harsh set of tubes if I've ever listened to one. I've never rolled opamps, but I feel that the LM4562 that I have sounds pretty neutral and detailed to me. I have an LT1364 from the previous owner but I've heard about the horrors of its DC offset affecting headphones. The LM4562 and WE408A combo is a charm for me. 
 

 
EDIT: updated pic
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[/size]

 

[shipsupt]

Thanks for the impressions.
 
I had heard that there were concerns about DC offset from the 1364, but never heard anyone actually reporting a problem caused by it... did you hear/read of some actual damage caused?
 
 

 

[zero7525]

What I've read is that because of the LT1364s opamp type (bi-polar), it produces DC offset in excess of +20mA. Apparently, too much DC offset can reposition the headphone's drivers, causing the sound to go to one side or worse, overheat and fry the headphones. 

 

[shipsupt]

Ok, that's pretty much the same thing I read.  I took the same cautious approach as you and have not tried the LT1364 in the LD I+... although I was tempted because there were quite a few folks who liked the sound and ran it for long periods with no issues.  

 

[LugBug1]

Quote:

Ok, that's pretty much the same thing I read.  I took the same cautious approach as you and have not tried the LT1364 in the LD I+... although I was tempted because there were quite a few folks who liked the sound and ran it for long periods with no issues.  

Yeah I tried it for a while with no probs, I quite liked the sound with Grado's as it added a bit more soundstage and smoothed the hardness that was there with stock. I gave it about the same amount of time as the 4562 (I found this one a little too neutral with Grado) but settled on the 2107. All depends on the phones your using though.  
 

 

[DanPluck]

I have had my Little Dot 1+ for about a month now and im constantly astonished at the sound it produces.  I started out with the standard opamp and EF92s and have been on quite a tube rolling journey. 
 
First of all i upgraded to the 2107 and was very pleased with the results, from there i tried the following tubes
Mullard M8161
Mullard EF91 - blue glass
Mullard CV4014
Colomor EF92
Brimar 6064
Voskhod 6ZH1P-EB
 
With Grado Sr125's my favorite tube was, by far the Brimar 6064, but now i have upgraded to Alessandro MS2i's and  im in love with the 6ZH1P-EB.  In my opinion the Voskhods are easily the best match to my setup, at £14 delivered for 10 you cant complain at all and they also give off a very satisfying glow
 
Source>Winamp 320 mp3/Flac>Xonar D2X>LittleDot 1+>Grado Sr125/Alessandro MS2i.
 
edit: The Voskhods seem to be significantly more resilient to interference.  My little dot is sat about 12 inches away from my PC, 850watt PSU and i get no background noise at all.  Compared to the m8161's who have a high pitched whine at loud volumes.

 

[henree]

Would it be okay to try two Opa 627 single opamps biased into class A? I also have a audio gd sun opamp laying around. I haven't tried it because I don't want to mess up anything.

 

[LugBug1]

Quote:

I have had my Little Dot 1+ for about a month now and im constantly astonished at the sound it produces.  I started out with the standard opamp and EF92s and have been on quite a tube rolling journey. 
 
First of all i upgraded to the 2107 and was very pleased with the results, from there i tried the following tubes
Mullard M8161
Mullard EF91 - blue glass
Mullard CV4014
Colomor EF92
Brimar 6064
Voskhod 6ZH1P-EB
 
With Grado Sr125's my favorite tube was, by far the Brimar 6064, but now i have upgraded to Alessandro MS2i's and  im in love with the 6ZH1P-EB.  In my opinion the Voskhods are easily the best match to my setup, at £14 delivered for 10 you cant complain at all and they also give off a very satisfying glow
 
Source>Winamp 320 mp3/Flac>Xonar D2X>LittleDot 1+>Grado Sr125/Alessandro MS2i.
 
edit: The Voskhods seem to be significantly more resilient to interference.  My little dot is sat about 12 inches away from my PC, 850watt PSU and i get no background noise at all.  Compared to the m8161's who have a high pitched whine at loud volumes.

Some nice tubes there. If you can, give the old Western 408 a go and let us know what you think. I think they work great with the 2107 opamp. For me they have good synergy; big soundstage, detail and weight. Best I've tried yet.
 

 

[cruizin caleb]

does matched/unmatched matter?

 

[n5750547]

Hello there fellow head fi creepers,
 
Couple of things (I will be reading this whole thread but I just want some advice so I can order my amp ASAP):
1. I have D5000's and I'm looking for a tube amp to suit. I was looking at the MkIII but was advised against it due to the amount of current that Denon's use. Does anyone have any experience matching the Mk1+ and D5000 (or MD5000/MD2000 as I'm thinking of getting the Markl mod with the money I will have saved by getting a cheaper amp)?
2. What are the best tubes to tighten the bass and bring forward the mids?
3. What are the main competitors (<$150) for the MKI?
 
 

 

[john57]

The Little Dot 1+ will work just fine with the Denons. Look at http://www.head-fi.org/forum/thread/563884/little-dot-tube-amps-vacuum-tube-rolling-guide  for you tube rolling options.

 

[DanPluck]

Quote:

Some nice tubes there. If you can, give the old Western 408 a go and let us know what you think. I think they work great with the 2107 opamp. For me they have good synergy; big soundstage, detail and weight. Best I've tried yet.
 

 
Thanks, to be honest i will probably end up selling them all except the Voshkods as they are easily my favorite.  Il try and pick up for 408's once i have sold some of my existing collection.


Quote:

does matched/unmatched matter?

 
Hasnt made a single bit of difference in my limited experience.