I have received my Lorenz made C3g in embossed flat black cans and am listening to them right now. I prefer the treble in them to the somewhat aggressive treble (in combination with some output tubes) in Siemens made C3g. I was very lucky and just paid EUR20 + shipping for the pair. I have been looking for them to and fro for a very long time. I have not wanted to pay the premium prices they usually go for. They sound clean and not lacking, to me. I agree with @gibosi's evaluation of them.
Little Dot Tube Amps: Vacuum Tube Rolling Guide
- Thread starter Dept_of_Alchemy
- Start date
Itzi
New Head-Fier
Hello! I've recently joined after lurking this thread for a while because I have some questions to ask about my Little Dot II. I've been enjoying it recently with Sylvania 6SN7 power tubes and Mullard EF92 driver tubes, and im loving this setup. I also have some Voshkod drivers coming in soon, excited to try those. However, I do have one issue.
When I was first setting up my LD, I was struggling to find out how to open it to change the internal dip switches, and I tried removing the front panel. This damaged the volume potentiometer, and now the LD can only go to about 20% volume before the right channel cuts out completely. The knob can also rotate a full 360 degrees (which I havent done while its powered on). I've looked into this and have heard about people replacing the potentiometer with an Alps Blue 100k, should I do this? I have a friend who's experienced in electronics and soldering, I just want to be sure that theres not another easier solution to my problem.
I've been circumventing this issue by using the LD as a pre-amp and raising the volume through my FiiO K5, but I'd like to just fix the issue anyway so I wont have to worry about whether or not its causing distortion or something.
Thank you!
When I was first setting up my LD, I was struggling to find out how to open it to change the internal dip switches, and I tried removing the front panel. This damaged the volume potentiometer, and now the LD can only go to about 20% volume before the right channel cuts out completely. The knob can also rotate a full 360 degrees (which I havent done while its powered on). I've looked into this and have heard about people replacing the potentiometer with an Alps Blue 100k, should I do this? I have a friend who's experienced in electronics and soldering, I just want to be sure that theres not another easier solution to my problem.
I've been circumventing this issue by using the LD as a pre-amp and raising the volume through my FiiO K5, but I'd like to just fix the issue anyway so I wont have to worry about whether or not its causing distortion or something.
Thank you!
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TrollDragon
Headphoneus Supremus
You have damaged the potentiometer and it needs to be replaced, there is no easy fix. I highly doubt that an ALPS Blue Velvet pot would fit in the MK2 without modifications to the board as the pin spacing is very different.
IMHO the best thing would be to just replace the broken pot with another one of the same type.
ALPS Blue Velvet specs.
Existing A100K pot specs:
Itzi
New Head-Fier
Okay, thank you for the advice. Which potentiometer would that be? I've tried looking it up but nobody has specified, unless I just dont know how to search properly. I tried reverse searching on TinEye but none of the results links work.You have damaged the potentiometer and it needs to be replaced, there is no easy fix. I highly doubt that an ALPS Blue Velvet pot would fit in the MK2 without modifications to the board as the pin spacing is very different.
IMHO the best thing would be to just replace the broken pot with another one of the same type.
ALPS Blue Velvet specs.
Existing A100K pot specs:
Edit: After using Reverse Image Search on google, I think I worked out the right one. Is it the b100k? I've found a few sets on amazon and if these are right, which do you think is the best? Thanks!
https://www.amazon.com/Taiss-Rotary...00k+potentiometer&qid=1618762699&sr=8-14&th=1
https://www.amazon.com/uxcell-Varia...9d1e3&pd_rd_wg=knFtz&pd_rd_i=B07JM2MZRW&psc=1
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TrollDragon
Headphoneus Supremus
The pictures I have seen of the Little Dot MK II uses an "A" type of pot, the ones you have linked on Amazon are "B" type and will not work correctly.
The best thing to do is take the bottom off of your amp and look at the pot to make sure it says A100K like the image below.
I can't find any "A" type pots on Amazon, but there are some on eBay from a US seller.
https://www.ebay.ca/itm/302359721877
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I think those two 220uF are the output caps... is there anybody here that replace them with something else with better quality? Which one and with what kind of results ?
Itzi
New Head-Fier
Hi again people 
I've been listening to a few different tubes the past weeks on my MkII, and I wanna know if anyone has had a similar experience to me with the Voskhod 6J1P-EV's with a pair of Sennheiser 650's? Going from the Mullard 6CQ6 to these was a pretty drastic change, and now comparing them to my GE JAN 5654s I have identified why I havent really gone back to them. I loved the bass response, the "fullness", and the highs of the Voskhods, but the soundstage felt very claustrophobic. Like, with the GEs, Mullards, and even stock drivers, although the soundstage is different, I can pick out where different instruments are and things at least sound distinct. With the Voskhods, everything feels very in my head and overwhelming. It does fine with slower music, like laid back jazz or rnb, but taking it anywhere near electronic, rock, and metal, leaves me fatigued within an hour or so. Vocals also feel distinctly too close.
As of now, the 5654s are the tubes I feel the most comfortable with. They dont have as wide a soundstage as the Mullards, but things just feel right and I tend to forget about the differences and just get lost in music easier, which the Mullards prevented me from doing with most albums due to their strong warmth. I really want to like the Voskhods, has anyone else had this experience and found it changes? I saw a lot of users talking about their long burn in time, but none of those posts mentioned anything about the soundstage, only that the harshness goes away. Thanks
I've been listening to a few different tubes the past weeks on my MkII, and I wanna know if anyone has had a similar experience to me with the Voskhod 6J1P-EV's with a pair of Sennheiser 650's? Going from the Mullard 6CQ6 to these was a pretty drastic change, and now comparing them to my GE JAN 5654s I have identified why I havent really gone back to them. I loved the bass response, the "fullness", and the highs of the Voskhods, but the soundstage felt very claustrophobic. Like, with the GEs, Mullards, and even stock drivers, although the soundstage is different, I can pick out where different instruments are and things at least sound distinct. With the Voskhods, everything feels very in my head and overwhelming. It does fine with slower music, like laid back jazz or rnb, but taking it anywhere near electronic, rock, and metal, leaves me fatigued within an hour or so. Vocals also feel distinctly too close.
As of now, the 5654s are the tubes I feel the most comfortable with. They dont have as wide a soundstage as the Mullards, but things just feel right and I tend to forget about the differences and just get lost in music easier, which the Mullards prevented me from doing with most albums due to their strong warmth. I really want to like the Voskhods, has anyone else had this experience and found it changes? I saw a lot of users talking about their long burn in time, but none of those posts mentioned anything about the soundstage, only that the harshness goes away. Thanks
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Have to admit that I haven't listened to the 6J1P-EV's but your description immediately struck me as something to try with the 5687 output tube that is sounding good to me, compared to 6N6P, but too 'distant'. These two tubes might actually be a good match as input and output. 5687 need an adapter that also can be used with E182CC which was the tube Little Dot intially was designed for and shipped with, until this E182CC became too scarce and expensive. I bought my adapters from 'xulingmrs' on eBay.Hi again people
I've been listening to a few different tubes the past weeks on my MkII, and I wanna know if anyone has had a similar experience to me with the Voskhod 6J1P-EV's with a pair of Sennheiser 650's? Going from the Mullard 6CQ6 to these was a pretty drastic change, and now comparing them to my GE JAN 5654s I have identified why I havent really gone back to them. I loved the bass response, the "fullness", and the highs of the Voskhods, but the soundstage felt very claustrophobic. Like, with the GEs, Mullards, and even stock drivers, although the soundstage is different, I can pick out where different instruments are and things at least sound distinct. With the Voskhods, everything feels very in my head and overwhelming. It does fine with slower music, like laid back jazz or rnb, but taking it anywhere near electronic, rock, and metal, leaves me fatigued within an hour or so. Vocals also feel distinctly too close.
As of now, the 5654s are the tubes I feel the most comfortable with. They dont have as wide a soundstage as the Mullards, but things just feel right and I tend to forget about the differences and just get lost in music easier, which the Mullards prevented me from doing with most albums due to their strong warmth. I really want to like the Voskhods, has anyone else had this experience and found it changes? I saw a lot of users talking about their long burn in time, but none of those posts mentioned anything about the soundstage, only that the harshness goes away. Thanks
5687 is electrically close to Melz 6N12S/6H12C that I am using but much easier to find and cheaper too.
Itzi
New Head-Fier
I've looked into the 5687, and honestly I might try this. Im really happy with my 6sn7's but I cant help but want to have fun with different combos, so Ill look into a pair of em with some adaptors sometime!
I finally replaced the malfunctioning potentiometer in my MKII with the one TrollDragon recommended, and even though I didnt expect it, there is a definite improvement in the sound of my amp! The Voskhods dont feel as cramped anymore, though I still prefer the GE's because of the clarity and slight soundstage they gain in exchange for weaker bass compared to the Voskhods. I also got a pair of Gold Brand Sylvania 5654's pretty cheap with Ebay's 5$ off code, so those will be coming in later this month for some more fun
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TrollDragon
Headphoneus Supremus
Glad to read that you got the pot fixed and all is good. Enjoy!
people ... WARNING!
I discoverd something not nice about C3g with our LD... at least with LDII (last hardware version)... unsing the adapter C3g works with LDII but works badly, if you measure the voltage at the heaters pins you discover that it is only 5,7V instead of the NOT lower then 6,0V admitted
from where this behaviour? from the C3g that has a heater current load of 390mA (each) against the nominal load of 175mA of a 5654... in practice the load is the double and the transformer, at that output, collapse
what is the problem? the problem is that a underpowerd heater can cause a shortening of the tube life down to few hours instead of the expected 10.000... and C3g are rare and expensive!
at the moment I replace the C3g with the 6HM5, that unfortunately are quite far to be the same, waiting to modify those adapters I've done for the C3g to be able to power those heaters with an external linear power supply (probably based on LM317 or 7805)
to better understand about underpowered heaters:
https://www.diyaudio.com/forums/tubes-valves/211731-heater-wiring-bad-ugly-3.html
https://audioxpress.com/article/the-internal-life-of-vacuum-tubes
I discoverd something not nice about C3g with our LD... at least with LDII (last hardware version)... unsing the adapter C3g works with LDII but works badly, if you measure the voltage at the heaters pins you discover that it is only 5,7V instead of the NOT lower then 6,0V admitted
from where this behaviour? from the C3g that has a heater current load of 390mA (each) against the nominal load of 175mA of a 5654... in practice the load is the double and the transformer, at that output, collapse
what is the problem? the problem is that a underpowerd heater can cause a shortening of the tube life down to few hours instead of the expected 10.000... and C3g are rare and expensive!
at the moment I replace the C3g with the 6HM5, that unfortunately are quite far to be the same, waiting to modify those adapters I've done for the C3g to be able to power those heaters with an external linear power supply (probably based on LM317 or 7805)
to better understand about underpowered heaters:
https://www.diyaudio.com/forums/tubes-valves/211731-heater-wiring-bad-ugly-3.html
https://audioxpress.com/article/the-internal-life-of-vacuum-tubes
TrollDragon
Headphoneus Supremus
Have you pulled the top cover off to see what the actual rating is on the transformer? If you could post a picture of the label that would be great for the thread as we already have a few other models.
pulling is enough or I have before to unscrew something?
uffff.... inside probably... outsid is completely flat, no screw ... nothing
ok, tomorrow I will check
ok, tomorrow I will check
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