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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 64

post #946 of 6949
Quote:
Originally Posted by gibosi View Post

It has been great fun following Audiofanboy on this journey through the great and wonderful land of unknown tubes. I am also retired and now have a little more time to play, but I may need to get another job to properly fund my current tube buying habit! :)

Yes it as been very interesting.but its affortable at least. i had a burson 160ds amp that i sold last week to help fund my new Burson Conductor that i got today should be good for a while i hope. This thing sounds incredible but i love my tubes theres something about tubes .i was checking out if i could use the dac out of the burson and plug it in the imput jacks of the littledot its a far better dac than my essence stx  soundcard. would you know if that would work dont want to risk damaging it if at all. 

post #947 of 6949
Quote:
Originally Posted by MIKELAP View Post

Yes it as been very interesting.but its affortable at least. i had a burson 160ds amp that i sold last week to help fund my new Burson Conductor that i got today should be good for a while i hope. This thing sounds incredible but i love my tubes theres something about tubes .i was checking out if i could use the dac out of the burson and plug it in the imput jacks of the littledot its a far better dac than my essence stx  soundcard. would you know if that would work dont want to risk damaging it if at all. 

I cannot imagine that it wouldn't work great. I have no experience with this unit, but I took a look on Burson Audio's webpage and I see that it has "DAC out" RCA jacks. Just connect those outputs to your Little Dot "Audio In" jacks. I am using an inexpensive little headphone DAC/Amp, a Fire Phoenix DAC-02, and in the same way, I connect the DAC out jacks to my Little Dot audio in. Works great! :)

post #948 of 6949
Quote:
Originally Posted by gibosi View Post

I cannot imagine that it wouldn't work great. I have no experience with this unit, but I took a look on Burson Audio's webpage and I see that it has "DAC out" RCA jacks. Just connect those outputs to your Little Dot "Audio In" jacks. I am using an inexpensive little headphone DAC/Amp, a Fire Phoenix DAC-02, and in the same way, I connect the DAC out jacks to my Little Dot audio in. Works great! :)

Thanks a lot i just tried it littledot sounds a lot better this amp is paying off already.

post #949 of 6949
Quote:
Originally Posted by MIKELAP View Post

Thanks a lot i just tried it littledot sounds a lot better this amp is paying off already.

I'm not surprised! Upgrading a DAC can be just as dramatic as swapping out tubes. And the Burson Conductor looks to have a top notch DAC, a major upgrade. So with the new DAC and those new Teslas, your Little Dot must be very happy! :)

post #950 of 6949

Hi all,

 

I am also retired, and I just would like to quote friend of mine who asked me what I am doing. I told him that I am retired. He answered: You are not retired, you are re-tired, rolling along!
 

Anyhow, decided to try the 6AU6A tubes. A friend gave me a little piece of wire which I cut to size and inserted in the sockets as per picture. Changed the jumpers to EF95 setting and plugged in the tubes. (Used my stainless steel tweezers with good results.)

 

Did not know if these tubes would work for me, so I ordered the least expensive GE tubes that I could find, less than $3 each, including shipping. A few days later I got a pair in the mail. These were made by RCA and had the name Bogen on them. Manufacturing date 1964-37; both the same. Oh well, what do you expect for 99c each +shipping? (Bogen made mainly commercial tube amps in the late 50's and early 60's. The brand exists today making PA amplifiers.) The original factory was in NJ, but there is nothing left of the factories - it is today the site of the Bergen Mall. Same fate for Tung Sol - nothing left except urban blight in Newark, NJ. Why can't I find much of the history of these manufacturers?)

 

Burned in the tubes for around 30 hours. First impression: the heaters are so dull and hidden that I cannot tell if the tubes are on from where I am sitting. I have to touch them to know that they are on - they get somewhat hot but not burning hot.

 

Listening: First impression enormous sound stage - on some recording the sound emanates from outside the right and left speakers! With the present setup in my room I cannot move my listening chair back far enough to get a center image - it is as if I am listening to two halves of the recording. Have to work on getting the sound stage right.

                Second impression: Extremely clean and detailed bass and low register. It is as if I brought home a refrigerator sized sub woofer instead of the 10" ones I have.

                Third impression: The mid range is not the sweetest, and the top end too bright. I have turn down the treble on my receiver to counteract the excessive brightness.

 

In summary: Fantastic tubes! Now I am just waiting to compare to the Tektronix matched tubes that I ordered.....

post #951 of 6949
Quote:
Originally Posted by mordy View Post

Hi all,

 

I am also retired, and I just would like to quote friend of mine who asked me what I am doing. I told him that I am retired. He answered: You are not retired, you are re-tired, rolling along!
 

Anyhow, decided to try the 6AU6A tubes. A friend gave me a little piece of wire which I cut to size and inserted in the sockets as per picture. Changed the jumpers to EF95 setting and plugged in the tubes. (Used my stainless steel tweezers with good results.)

 

Did not know if these tubes would work for me, so I ordered the least expensive GE tubes that I could find, less than $3 each, including shipping. A few days later I got a pair in the mail. These were made by RCA and had the name Bogen on them. Manufacturing date 1964-37; both the same. Oh well, what do you expect for 99c each +shipping? (Bogen made mainly commercial tube amps in the late 50's and early 60's. The brand exists today making PA amplifiers.) The original factory was in NJ, but there is nothing left of the factories - it is today the site of the Bergen Mall. Same fate for Tung Sol - nothing left except urban blight in Newark, NJ. Why can't I find much of the history of these manufacturers?)

 

Burned in the tubes for around 30 hours. First impression: the heaters are so dull and hidden that I cannot tell if the tubes are on from where I am sitting. I have to touch them to know that they are on - they get somewhat hot but not burning hot.

 

Listening: First impression enormous sound stage - on some recording the sound emanates from outside the right and left speakers! With the present setup in my room I cannot move my listening chair back far enough to get a center image - it is as if I am listening to two halves of the recording. Have to work on getting the sound stage right.

                Second impression: Extremely clean and detailed bass and low register. It is as if I brought home a refrigerator sized sub woofer instead of the 10" ones I have.

                Third impression: The mid range is not the sweetest, and the top end too bright. I have turn down the treble on my receiver to counteract the excessive brightness.

 

In summary: Fantastic tubes! Now I am just waiting to compare to the Tektronix matched tubes that I ordered.....


Glad to see you had the same kind of impressions Gibosi and I had about the 6AU6 tubes! There is great potential in that tube family -at a fraction of the cost of the best 6AK5 and EF92/91s- and ample supply to last for a few decades. About your matched Tek pair, did you get 8425A/6AU6A tubes? After testing quite a number of similar tubes of different families in the past couple of weeks, there is at least one conclusion I've reached: the industrial/computer rated tubes are usually the best the US manufacturers made, often better than the mil spec versions. Which makes perfect sense in a way; on a Tek oscilloscope, you'd need matched high quality (read hi-fi) signal tubes -sometimes in parallel by lots of 14 or 16!- that just keep on being high quality but less and less powerful until they are replaced by whole lots, whereas military tubes just need to be reliable, i.e. not replaced often -"will keep on sounding the way they do for a long time" or so someone mentioned here a few pages ago.

 

Anyway, if I were to try another US tube type right now, I'd get an industrial/computer type, and I'd get it in that order (knowing that the tubes may not be that different but just more or less "selected"):

- Industrial company certified or matched (like the Tektronix tubes)

- Industrial military (not necessarily mil spec then; for the 6AU6 family,  the 8425A are industrial/computer rated but the 6136 and 6AU6WA/B/C are "just" premium/mil spec tubes)

- Industrial "consumer" grade (which probably aren't really consumer grade though)

 

Hoping this helps someone's fleebay adventures...

 

Edit: Sadly, I am not retired nor close to being retired by any fair margin, hence my irregular posting lately...


Edited by Audiofanboy - 3/28/13 at 4:26pm
post #952 of 6949
Quote:
Originally Posted by Audiofanboy View Post


Glad to see you had the same kind of impressions Gibosi and I had about the 6AU6 tubes! There is great potential in that tube family -at a fraction of the cost of the best 6AK5 and EF92/91s- and ample supply to last for a few decades. About your matched Tek pair, did you get 8425A/6AU6A tubes? After testing quite a number of similar tubes of different families in the past couple of weeks, there is at least one conclusion I've reached: the industrial/computer rated tubes are usually the best the US manufacturers made, often better than the mil spec versions. Which makes perfect sense in a way; on a Tek oscilloscope, you'd need matched high quality (read hi-fi) signal tubes -sometimes in parallel by lots of 14 or 16!- that just keep on being high quality but less and less powerful until they are replaced by whole lots, whereas military tubes just need to be reliable, i.e. not replaced often -"will keep on sounding the way they do for a long time" or so someone mentioned here a few pages ago.

 

Anyway, if I were to try another US tube type right now, I'd get an industrial/computer type, and I'd get it in that order (knowing that the tubes may not be that different but just more or less "selected"):

- Industrial company certified or matched (like the Tektronix tubes)

- Industrial military (not necessarily mil spec then; for the 6AU6 family,  the 8425A are industrial/computer rated but the 6136 and 6AU6WA/B/C are "just" premium/mil spec tubes)

- Industrial "consumer" grade (which probably aren't really consumer grade though)

 

Hoping this helps someone's fleebay adventures...

 

Edit: Sadly, I am not retired nor close to being retired by any fair margin, hence my irregular posting lately...

Chanceux.

post #953 of 6949

Hi Audiofanboy,

 

I bought a pair of Tektronix matched selected tubes, (as per your suggestion) and this is what the seller wrote me regarding the regular 6AU6A and the Tektronix:

 

"Checked tubes were hand selected for certain characteristics that sometimes included greater transconductance which may mean a longer life. Checked and selected tubes were the highest grade tubes tubes Telefunken could find for the very high end machines they were making. I always find "Checked" and "Selected" tubes to be stronger, and have great sound. Does it mean the unchecked tubes don't sound great? No. I would opt for checked tubes in a 6au6 for a few dollars more. I hand test and select these tube and make sure they match. Hope that helps."
 

post #954 of 6949
Quote:
Originally Posted by mordy View Post

These were made by RCA and had the name Bogen on them. Manufacturing date 1964-37; both the same. Oh well, what do you expect for 99c each +shipping? (Bogen made mainly commercial tube amps in the late 50's and early 60's. The brand exists today making PA amplifiers.) The original factory was in NJ, but there is nothing left of the factories - it is today the site of the Bergen Mall. 

 

I remember Bogen! I was in a rock band in the 1960s and Bogen PA systems were very common at that time. I had no idea this company was still in business and making PA systems today.

 

And of course, I am glad that your RCA 6AU6s are "fantastic"! Similar to you, I first bought some cheap standard GE 6AU6s and was so impressed, I immediately purchased a pair of 8425As. These are still my No 1 tubes, but then, we don't know what unknown tubes Audiofanboy is planning to audition next. :)

post #955 of 6949

Am i the only one on this thread on their 20's? LOL

post #956 of 6949
Quote:
Originally Posted by mab1376 View Post

Am i the only one on this thread on their 20's? LOL


Nope, I'm in my 20s too lol, albeit late 20s, but still.

 

Mordy, I wouldn't be surprised if these, while etched 6AU6A -like my and Gibosi's 8425A- were also silk-written 8425A underneath the Tek tag, since it appears that's what they used. At any rate, these should be fabulous tubes!

post #957 of 6949

Hi Audiofanboy,

 

The ones I ordered are listed as 8425A/6AU6A GE NOS 60's Tektronix tubes. The picture just shows two tubes with the Tektronix label and numbers, but I am pretty sure that these are the ones. Paid less than $6:50 each including shipping, which make these tubes the 2nd most expensive tubes I bought. Should be here in a couple of days and will report back when I try them out.
 

The RCA Bogen tubes are dated 1964 which seems a little strange since one source stated that tube amp production seized in 1963. Tidbit: Found a post that said that if you ordered 1000 tubes or more you could get your name on them.

 

As I am writing this, I am listening to these tubes now and I am marveling at the clarity and bass. They tubes seem to have improved - is it possible that they require a longer break in period than say 30 hours?

post #958 of 6949
Quote:
Originally Posted by mab1376 View Post

Am i the only one on this thread on their 20's? LOL

Ya your the lucky one lol . 

post #959 of 6949

Seems I hit the age kind of in the middle between you two groups.

 

Actually, I wrote a mail to Dept_of_Alchemy to ask whether he could edit his opening post to to point at the the workable but not officially supported families of tubes but it seems he hasn't been active for a while.

 

I try to refrain from my tube rolling addiction these days but I am not sure I can overcome it fully. *Cautious look at the 6AU6A tubes* ;)


Edited by Acapella11 - 3/29/13 at 1:37pm
post #960 of 6949

I got my 6AU6A tubes, I just need to make a jumper to be able to use them, also need to swap back to the 6AK5 setting.

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