[sling5s]

Went through briefly the thread.  I have Grado RS1.  Used to have MAD EAR but considering Little Dot 1+ for the RS1.
It seems the recommended opamps are: op2107 and LT1364cn8
Recommend Tubes: Mullard M8161 and Mullard ef91
 
Which is best?
 
thanks
 
I see that the M8161 is part of the EF92 Family of tubes.
 
I see now that the EF92: M8161 with op2107 is probably the best followed by Mullard CV131

 

[sling5s]

Mullard M8161 or Mullard CV131 or Mullard CV4010 for Grado RS1?

 

[gibosi]

Quote:

Mullard M8161 or Mullard CV131 or Mullard CV4010 for Grado RS1?

 
CVNNNN numbered tubes (that is CV + 4 digits) are the improved version of CVNNN (3 digits), and are generally considered be to better. Also, M8161 and CV131 are EF92, whereas CV4010 is EF95. So if you are thinking of getting an M8161 or CV131, I would recommend that you look for the improved CV4015. If you want an EF91, the best tube in my experience is the GEC CV4014.
 
It can be somewhat confusing, I know....
 
CV4010 = EF95
CV4014 = EF91
CV131 < CV4015 = EF92
 
As to which might go best with Grado headphones, sorry, I can't help you....
 
 

 

[sling5s]

Sorry, stupid question again, but do you only need one op2107 or a pair for this amp?

 

[gibosi]

Quote:

Sorry, stupid question again, but do you only need one op2107 or a pair for this amp?

 
This is a dual op amp, so you need only one of them.
 
http://www.ti.com/product/opa2107

 

[sling5s]

thanks

 

[Sony Slave]

Quote:

 
This is a dual op amp, so you need only one of them.
 
http://www.ti.com/product/opa2107

Do you have any idea what Tubes would be best suited for the Shure SRH440's? I would like more bass, more resolving highs, and a much longer decay if possible.
 
Hope you can help.

 

[gibosi]

Quote:

Do you have any idea what Tubes would be best suited for the Shure SRH440's? I would like more bass, more resolving highs, and a much longer decay if possible.
 
Hope you can help.

 
I am not familiar with the Shure SRH440, so I don't have a clue. But even so, it would be very helpful to know what tubes you are using now.

 

[Sony Slave]

Quote:

 
I am not familiar with the Shure SRH440, so I don't have a clue. But even so, it would be very helpful to know what tubes you are using now.

I don't have a an amp yet, I plan on buying it tomorrow  that's when I get paid, so hypothetically I would be using the stock tubes.
I know, I know it sounds dumb, I wan't advice on something I never heard before, but I just want some sort of idea of what too look for.

 

[gibosi]

Quote:

I don't have a an amp yet, I plan on buying it tomorrow  that's when I get paid, so hypothetically I would be using the stock tubes.
I know, I know it sounds dumb, I wan't advice on something I never heard before, but I just want some sort of idea of what too look for.

 
Unless you are getting upgraded tubes, I feel quite safe in saying that almost any tube you get will be an improvement over the stock Chinese tubes.
 
In the meantime, go to page one of the "Little Dot Tube Amps: Vacuum Tube Rolling Guide" forum. There you will find an excellent introduction to the standard tubes which can be used in your Little Dot which will help you decide which tubes you might want to try.
 
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide

 

[gibosi]

LME49990 opamp
 
Perhaps like a lot of forum members, shortly after purchasing my LD 1+, I rolled in a OPA2107 opamp, and for sure at the time, I felt it was a significant improvement over stock. Recently however, I have been feeling that this chip is rather dark, as it seems the highs are rolled off to some degree, and I have been searching for other opamps to try. One that stood out was the LME49990. Actually this is a single opamp, so it is necessary to install two of them on a DIP8 adapter. As I am not all that comfortable with a soldering iron, I purchased a pre-assembled unit from this vendor:
 
http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER-/190888281070?pt=US_Amplifier_Parts_Components&hash=item2c71d403ee
 
I rolled it in last night and based on my impressions so far, this chip delivers on all counts. The base has more weight and slam than the OPA2107 and the mids are more neutral. In contrast, the mids on the OPA2107 are a bit more forward, and sometimes vocals almost seem to come across as a bit shouty. And the highs... Extended, clean and clear, with a bit of sparkle. Not rolled off like the OPA2107. So in a nutshell, this is a very neutral and transparent opamp which allows the true nature of the driver tubes to shine through. In fact, some tubes that I had previously thought too forward, are now much easier on my ears and even quite pleasant.
 
In short, I am very pleased with this opamp, but I am not all that surprised. I figured that if these opamps were specifically selected for use in the Parasound Halo CD 1, they just might be good enough for my 1+. lol
 
Recommended 

 

[Iron58p]

Hi Gibosi
 
this is my forst post here, yesterday was arrived my Little dot I+ with Valvo 6CQ6.
 
I have taken from you and other people on this forum the fever of tube rolling 
 
Fist thing : the tubes Valvo are not hot until now, but have a temperature a little bit more than human body, and are increasing slowly from the first moment ; may be it's normal, and between some days things will be normal.
 
Looking for your last post ( thank's for sharing !! ), are arriving 2 opa LME49990 insatalled on a DIP8 adapter.
 
I need your help please, mavy tubes are arriving ( looking for your impressions ), and for some of these i will cut away 2 pins, but i don't want to cut the wrong pins.
For now i prefer to cut pins then strapping.
 
Sorry for my basic english, i live in Italy.
 
And then, if you can, write what configuration ( EF92 or EF95 ) for each couple of tubes so i can stamp your reply for the future rolling :
 
Siemens 6AK5W
 
Telekunken EH 900S
 
Tesla 6F32-6AK5
 
Lorenz 6AV6-EBC91
 
Mullard CV4015 
 
Sylvania 6AV6
 
Miniwatt Z&I EH90 6CS6
 
Ibm 1680 6BE6
 
Russian 6A2P 6BE6 EK90
 
Jan GE 5654W 6AK5 CV4010
 
Voskhod 6J1P-EV (EF95 6F32 6AK7 Gold-Platinum grid
 
Thank's for the help
 
Quote:

LME49990 opamp
 
Perhaps like a lot of forum members, shortly after purchasing my LD 1+, I rolled in a OPA2107 opamp, and for sure at the time, I felt it was a significant improvement over stock. Recently however, I have been feeling that this chip is rather dark, as it seems the highs are rolled off to some degree, and I have been searching for other opamps to try. One that stood out was the LME49990. Actually this is a single opamp, so it is necessary to install two of them on a DIP8 adapter. As I am not all that comfortable with a soldering iron, I purchased a pre-assembled unit from this vendor:
 
http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER-/190888281070?pt=US_Amplifier_Parts_Components&hash=item2c71d403ee
 
I rolled it in last night and based on my impressions so far, this chip delivers on all counts. The base has more weight and slam than the OPA2107 and the mids are more neutral. In contrast, the mids on the OPA2107 are a bit more forward, and sometimes vocals almost seem to come across as a bit shouty. And the highs... Extended, clean and clear, with a bit of sparkle. Not rolled off like the OPA2107. So in a nutshell, this is a very neutral and transparent opamp which allows the true nature of the driver tubes to shine through. In fact, some tubes that I had previously thought too forward, are now much easier on my ears and even quite pleasant.
 
In short, I am very pleased with this opamp, but I am not all that surprised. I figured that if these opamps were specifically selected for use in the Parasound Halo CD 1, they just might be good enough for my 1+. lol
 
Recommended 
 
 

 

[gibosi]

Hello Iron58p,
 
First it is normal for tubes to run hot. And some tubes run hotter than others....
 
> I need your help please, mavy tubes are arriving ( looking for your impressions ), and for some of these i will cut away 2 pins, but i don't want to cut the wrong pins.
> For now i prefer to cut pins then strapping.
 
For sonic impressions of these tubes, I suggest you check out the "Little Dot Tube Amps: Vacuum Tube Rolling Guide" forum:
 
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide#post_7625989
 
At the top and bottom of the page, you will see a magnifying glass and the text "Search this Thread". Use this feature to search for impressions on any tubes you are interested in.
 

---

 

Siemens 6AK5W  (EF95)
 
Telekunken EH 900S  (EF95 or EF92 - choose the one that sounds best to you. However, I prefer EF95, pins 1 and 7 strapped)
 
Tesla 6F32-6AK5  (EF95)
 
Lorenz 6AV6-EBC91  (EF92 and cut pins 5 and 6)
 
Mullard CV4015   (EF92)
 
Sylvania 6AV6  (EF92 and cut pins 5 and 6)
 
Miniwatt Z&I EH90 6CS6  (EF95 or EF92 - choose the one that sounds best to you. However, I prefer EF95, pins 1 and 7 strapped)
 
Ibm 1680 6BE6  (EF95 or EF92 - choose the one that sounds best to you. However, I prefer EF95, pins 1 and 7 strapped)
 
Russian 6A2P 6BE6 EK90  (EF95 or EF92 - choose the one that sounds best to you)
 
Jan GE 5654W 6AK5 CV4010  (EF95)
 
Voskhod 6J1P-EV (EF95 6F32 6AK7 Gold-Platinum grid  (EF95)
 
Check out post 1154 on page 77 in the "Little Dot Tube Amps: Vacuum Tube Rolling Guide" forum for more info on how to use these tubes:
 
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055
 
 

---

 

How to determine which pins to cut in order to use 6AT6/EBC90 and 6AV6/EBC91 tubes:

 
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1065#post_9363431
 
(Ignore info about the 6J4. The 6AT6/EBC90 and 6AV6/EBC91 tubes sound much better....
 
And a picture: Pins 5 and 6 are cut off. Pin 7 is on the left.
 

 
Happy tube rolling!

 

[Iron58p]

Thank's again Gibosi for your kindness.
 
I am  a novice about tube rolling, but i have 5 ampli and many headphone, including Alessandro MSPRO, and i love that sound.
 
I have read the thread "Little Dot Tube Amps: Vacuum Tube Rolling Guide", but is hard to remember the info fragmented, is very long.
 
You wrote : "Ignore info about the 6J4. The 6AT6/EBC90 and 6AV6/EBC91 tubes sound much better....", that mean " EF92 and cut pins 5 and 6" is what you want to tell ?
 
And again, if i don't cut 2 pin, what can happen ? that the music quality is not good or i can damage something ?
 
And if i cut 2 pins and i wrong the number for example, there is a way to go back to the original ?
 
I am thinking, what is the more easy mode between cut and strapping pins, but in that sense i have no experience to decide.
 
First, i don't know what kind of metal is used for strapping, i have read that must be stranded wire and thin.
Ehm, 26 gauge what mean ? i don't know what mean gauge.
 
Second, i must to find a nipper very small.

 

[gibosi]

Quote:

Thank's again Gibosi for your kindness.
 
I am  a novice about tube rolling, but i have 5 ampli and many headphone, including Alessandro MSPRO, and i love that sound.
 
I have read the thread "Little Dot Tube Amps: Vacuum Tube Rolling Guide", but is hard to remember the info fragmented, is very long.
 
You wrote : "Ignore info about the 6J4. The 6AT6/EBC90 and 6AV6/EBC91 tubes sound much better....", that mean " EF92 and cut pins 5 and 6" is what you want to tell ?
 
And again, if i don't cut 2 pin, what can happen ? that the music quality is not good or i can damage something ?
 
And if i cut 2 pins and i wrong the number for example, there is a way to go back to the original ?
 
I am thinking, what is the more easy mode between cut and strapping pins, but in that sense i have no experience to decide.
 
First, i don't know what kind of metal is used for strapping, i have read that must be stranded wire and thin.
Ehm, 26 gauge what mean ? i don't know what mean gauge.
 
Second, i must to find a nipper very small.

 
You must cut pins 5 and 6 and use the EF92 setting to listen to 6AT6/EBC90 and 6AV6/EBC91 tubes. It is the only way. If you do not cut the pins, there is no damage, but then you will hear nothing. And of course, if you cut the wrong pins, the tube is worthless. You cannot put the pins back on the tube. I suggest that you purchase 5 or 10 very cheap 6AV6, so you can practice cutting pins. After you have had success cutting pins on a few really cheap tubes, you will feel more comfortable cutting pins on more expensive ones.  
 
And yes, you will need to purchase a pair of wire cutters like this:
 
 
 
If you decide to strap, I suggest 28 or 30 gauge stranded wire. "Gauge" is the standard way to indicate wire thickness. The bigger the number, the smaller the wire. So 26 gauge is thicker than 30 gauge. If you have a pair of cheap broken IEMs, that wire is very small and should be perfectly fine.