or Connect
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Little Dot Tube Amps: Vacuum Tube Rolling Guide
New Posts  All Forums:Forum Nav:

Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 293

post #4381 of 10504
Quote:
Originally Posted by gibosi View Post
 

The 6HM5 is plug and play using the EF95 setting.

THANKS

post #4382 of 10504
Quote:
Originally Posted by Audiofanboy View Post
 

 

Very curious to know whether or not there's an audible difference with the external power supply and regulator!

 

At any rate, that's a pretty rigged MKI+ lol... Looks more like something on the dashboard of the Delorean in "Back to the Future" than like a tube amp!

 

I have been using the external power supply with a 6SN7 for a few days now. I wasn't entirely happy as there was some hum and random interference too. A bit of reading lead me to the solution. You need to tie the negative heater lead to ground. This is because when using a wall adapter there is no path to ground for the heater supply at all. I took an old RCA cable, cut off one end, and connected the shield part of the cable to the negative heater lead. Then connected the RCA plug to one of the LD RCA line-out connectors that I don't use. This is a convenient and tidy way to get a ground connection.

I now have no hum.

post #4383 of 10504

Just got in a batch of 6DJ8 derivatives. One is a Tung Sol X155/6BZ8 tube. The silk screen says Tung Sol Made in USA 812-3. However, there is an etched designation LC2F on the tube, which looks like a Philips(?)  designation to me.

 

This tube also has an unusual green insert in the bottom piece of glass. Here is a picture of this exact tube from three different brands - they all look to come from the same source. (The etched codes are slightly different)

 

 

 

 

The etched code on my tube is LC2F.  Can anybody decipher it?

 

Semi educated wild guess: In the Philips designation system L stands for Mazda - Belgium. Could this be a Mazda tube made in March 1962?

 

BTW, the sound is excellent on first impression. Tremendous detail, ferocious slam - could this be a poor man's 6922? Or in LD MK9 speak: "Low frequency response can dive deeper, more solid, soprano Alto can be more transparent ."

 

Shoot out has to wait a little - got another 7 tubes from the same tube family to check out.....


Edited by mordy - 12/16/13 at 9:27pm
post #4384 of 10504

I just sold my left kidney on ebay... Wait no, that's not right. I just managed to win a set of two tubes on ebay that basically are supposed to be the best 6DJ8 types ever made. I paid an unreasonable amount of money for these, compared to all our old pentodes, but reasonable enough if it sounds good in my amp.

 

So, yeah, one 7L3 delta8B Holland-made Amperex 6922 pinched waist D-getter, along with a 7L4 delta9E Holland-made 6922  D-getter (regular waist).

 

I just couldn't resist when I saw that the price wasn't even that high all in all (the last pairs of pinched waist Holland 6922 I found were auctioned for $600+ and $400+, so it's all very relative in the end; I only ever paid the price of pair of 6N30P-DR for these tubes...).

 

Anyway, should be an interesting experiment, seeing as this time around there really isn't supposed to be anything better. We shall see. I wouldn't worry about selling them easily if I were suddenly strapped for cash...

 

I also have a single EDIT: VR0 *0E US-made Amperex 7308 coming; I paid for it like a week ago, but the seller just doesn't seem that inclined to actually send the darn tube. Bad reviews, they are a-coming, I tell you... Not that I care that much, considering the cheap(ish) price I paid for that tube, compared to the once above...


Edited by Audiofanboy - 12/17/13 at 1:36am
post #4385 of 10504
Quote:
Originally Posted by Ctritical Bill View Post
 

I have been using the external power supply with a 6SN7 for a few days now. I wasn't entirely happy as there was some hum and random interference too. A bit of reading lead me to the solution. You need to tie the negative heater lead to ground. This is because when using a wall adapter there is no path to ground for the heater supply at all. I took an old RCA cable, cut off one end, and connected the shield part of the cable to the negative heater lead. Then connected the RCA plug to one of the LD RCA line-out connectors that I don't use. This is a convenient and tidy way to get a ground connection.

I now have no hum.

 

The LD 1+ has only one pair of RCA jacks, Audio In, so no unused jacks....  I guess I need to figure out another way.....

post #4386 of 10504
Quote:
Originally Posted by gibosi View Post
 

 

The LD 1+ has only one pair of RCA jacks, Audio In, so no unused jacks....  I guess I need to figure out another way.....


A wire from the filament negative to any of the case screws should suffice as well.

post #4387 of 10504

Finally, to finish the Amperex face-off, is a Heerlen E188CC, VR2 1960. Aside from the very old and rare tubes that AFB has just snared, this is the queen of the Amperex line. Comparing it to the Heerlen E88CC, VL6, 1961, I found it to have essentially the same sound signature, with lush mids and great detail. But I felt that the E188CC was a tad bit quieter, and hence, a bit more detailed.

 

And then I thought I should roll in a 1960 BugleBoy and a 1967 Orange Globe. These two tubes have a sound signature very similar to the E188CC with that same characteristically lush, liquid mid-range. I would say that these tubes give you 90% to 95% of a E188CC.

 

So, are the E88CC and E188CC really worth the premium price? I would say yes with some qualifications.

 

These premium tubes are quieter, they have better detail, and they will last longer. In the case of the E188CC, the fact that the two triodes are very closely matched will provide better balance. So if extreme detail is your thing, then of course you should get these tubes. However, if you have been happily enjoying a late 1960s Orange Globe with a halo getter, these refinements will likely not knock your socks off. I find them to be very subtle. So I encourage you to continue to enjoy that Orange Globe. And if you do happen to stumble across a very good deal on a Heerlen E88CC or E188CC, grab it knowing that you are going to like it. :)

 

And with this, I have finally worked through my stable of Philips tubes....

 

Next up will be the Voskhod 6N23P (X-75). Recently, this has been my go-to tube. It has great liquidity and flow, and it is also very detailed and transparent. In very complex passages one can follow each instrument with ease, everything is very clear and distinct. However, I have not yet had a chance to directly compare it to the best of the Heerlens, the E188CC....

post #4388 of 10504
Quote:
Originally Posted by TrollDragon View Post
 

A wire from the filament negative to any of the case screws should suffice as well.

 

I will give this a try! Thanks! :)

post #4389 of 10504
I am so pumped to play with the big boys....that is all
Edited by mojorisin35 - 12/16/13 at 9:55pm
post #4390 of 10504
Quote:
Originally Posted by Kestovitutus View Post

I find the Yugos good, but they have little bit "metallic" sound in my gear. 

Sylvania 6HM5 has very good highs and very pronouncive bass, but they can sound little bit "crowded" in upper mids/highs.


With the yugos I felt the same way as well when they were new however after 20-50 hrs it is gone. Top notch if you can hang in there.yrmv
Gary
post #4391 of 10504
Quote:
Originally Posted by gibosi View Post
 

Finally, to finish the Amperex face-off, is a Heerlen E188CC, VR2 1960. Aside from the very old and rare tubes that AFB has just snared, this is the queen of the Amperex line. Comparing it to the Heerlen E88CC, VL6, 1961, I found it to have essentially the same sound signature, with lush mids and great detail. But I felt that the E188CC was a tad bit quieter, and hence, a bit more detailed.

 

And then I thought I should roll in a 1960 BugleBoy and a 1967 Orange Globe. These two tubes have a sound signature very similar to the E188CC with that same characteristically lush, liquid mid-range. I would say that these tubes give you 90% to 95% of a E188CC.

 

So, are the E88CC and E188CC really worth the premium price? I would say yes with some qualifications.

 

These premium tubes are quieter, they have better detail, and they will last longer. In the case of the E188CC, the fact that the two triodes are very closely matched will provide better balance. So if extreme detail is your thing, then of course you should get these tubes. However, if you have been happily enjoying a late 1960s Orange Globe with a halo getter, these refinements will likely not knock your socks off. I find them to be very subtle. So I encourage you to continue to enjoy that Orange Globe. And if you do happen to stumble across a very good deal on a Heerlen E88CC or E188CC, grab it knowing that you are going to like it. :)

 

And with this, I have finally worked through my stable of Philips tubes....

 

Next up will be the Voskhod 6N23P (X-75). Recently, this has been my go-to tube. It has great liquidity and flow, and it is also very detailed and transparent. In very complex passages one can follow each instrument with ease, everything is very clear and distinct. However, I have not yet had a chance to directly compare it to the best of the Heerlens, the E188CC....

 

Quoting gibosi, as per usual, makes it look we're doing some kind of warped comedy show about tubes, but whatever.

 

Re the Heerlen E188CC VR2 1960: indeed, after some moments of doubt with that tube after 30h or burn-in, a simple switch to the US 6922 made me realize a few things. First, the E188CC is quiet, dead quiet; and that black background really helps details stand out in a natural way with a texture of sorts. And second, that tube is good, like really good. Though I still miss a little of that bass punch the US 6922 has, the E188CC - the early models at least, can't vouch for the later ones - does everything else better. After 50+ of burn-in, I have little doubt that this is my best tube. Maybe not for long lol, but my best tube.

 

I really believe that it's worth paying a little extra for, honestly. This could be your end-game tube, and it is for many Lyr users. Again, you can buy singles with a Dario or RT, or even Mullard brand for very decent prices (no, not $8 per triode lol, but hey if they last double the time a regular double triode does, can't we say it's worth four triodes, so $32?). All it takes is patience; and a little cash, granted. I'm using a new method with 6DJ8 tubes personally: no more museum-like collecting of otherwise useless tubes; now I just sell all the - rather premium - tubes I buy and know I won't be using. I just can't afford to have 30-200$ tubes collecting on a shelf, and it always makes someone else happy to get premium tubes easily lol (and it helps finance my ever more expensive tubes too, somewhat...).

 

Gibosi, did you ever reach a conclusion on the French Suresnes (10 miles away from my house) made E188CC? I keep reading that that tube is like the alternative, not the best of the best, but an excellent take on the E188CC type that many prefer to the Heerlen ones. Is that so? Or should people just focus on getting that Groupon order of cheap Heerlen E188CC going instead lol?

post #4392 of 10504
Quote:
Originally Posted by CollectoR13 View Post

Mhm so were do I get these damn adapters now? smily_headphones1.gif
The ebay seller doesn't have them anymore...
Do you guys know another source for them or is anybody willing to build me some?

No Ideas? wink.gif
post #4393 of 10504
Which adapters are you talking about?
post #4394 of 10504
Adapters to use 6sn7 instead of 6n6p.
They were discussed few pages back and there was a ebay link, but the auction ended and Google didn't help at all...
post #4395 of 10504

These ones here will work as the 6CG7 has the same pinout as the 6N6P.

:beerchug:

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Little Dot Tube Amps: Vacuum Tube Rolling Guide