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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 406

post #6076 of 10502
Quote:
Originally Posted by gibosi View Post
 

 

Mordy is using a different sub-miniature than the one I used. The one I used, Sylvania 7963, is expensive, over $20. But he is using a Raytheon 6832. and these are much cheaper. For example:

 

http://www.ebay.com/itm/Raytheon-Jan-6832-Submini-dual-Triode-Matched-Pair-Excellent-NOS-tubes-/271171966719

Thanks G! i just bought it from your link.:biggrin:

post #6077 of 10502
Quote:
Originally Posted by mordy View Post
 

Hi Gibosi,

 

Received a lot of seven 6080 tubes. They are from different years; all but one of them is made by RCA, the other one is a GE. They sound different, perhaps because of slightly different construction and usage.

 

The best of these, a 1956 and 1960 RCA and the GE, sound very good with a very strong punchy bass which pairs very well with my Audio Technica headphones which are bass shy.

 

In comparison to my Coke Bottle 1976 RCA 6AS7G tube the 6080's have better bass, but the 6AS7 has more detail. These 6080 tubes also play louder than the 6AS7 although both have an amplification factor of 2.

 

At this time the nod goes to the 6080. However, what I really would want to do is to use these 6080s as power tubes, but I haven't figured out how to do it. Perhaps buying two octal breadboards and two 9-pin socket extenders. Then use solid 18 gauge insulated copper wire (which is the same thickness as the tube pins) and connect the wires to screw terminals on each breadboard. The other end of the wire I could just strip and push down into the socket extender.

 

Two separate wires would go to an external power supply rated 10A. Do I need two external power supplies, or would one do? The 6080 tubes draw 2.5A each.

 

Right then folks, here we go - at last! - the 6AS7G as power tube (only 1, in the right channel at the moment, with the Psvane CV181-T II in the left).

 

Well, all I can say at the moment is...WOW! I wasn't really expecting anything could outdo the TS 7N7 in my setup, but after about half an hour (I believe these tube types need a fair warm-up) I just could not believe it...initial impressions were greater dynamics, more detail especially in the upper bass/lower mids, and an even more expansive soundstage (assisted in my Clannad tracks by more of the reverb). A much more intensive listening appraisal will have to wait I'm afraid - peering into the MKIV SE's innards, while holding the temperature probe hard against the cathode resistor and watching the temp readout with much trepidation was NOT very conducive to proper sound assessment, lol!!

 

Anyway, much to my great relief the temperature didn't do heart-stopping jumps, but a gradual rise to 56/57C after an hour's continuous playing (the 6SN7-types held at 28C).

Better still, it stayed there after 2 hours; then just 58C at 3 hours, and 59C at 4 hours. As I believe this is way below the maximum rated temp for such a resistor, it looks as though we may be OK with these tubes after all...if so, I think this could  be just as  great a leap for our LDs (the MKIV SE, anyways) as was given by the C3g drivers. I am over the moon - at present at least! The prospect of BOTH RCAs up and running is getting me all of a lather:tongue_smile:.

 

As for setup, mordy, I am using a 6SN7 to 6C7G adapter, with pins 4 & 5 of the latter chopped off, all bar enough to solder the external heater wires (then covered with tape, of course).

I managed to find a voltage regulator rated at 8A, which at the moment with just 1 tube is working fine - no real heat from it even after 4 hours' use. It is on amazon.com for $10.96 (free shipping), and .co.uk for £4.99 (free UK shipping). It is listed as "Input AC/DC 12-45V to Output AC/DC 0.7-21V 8A converter board step-down voltage regulator module"... It has no readout, so you do need a meter, which is good for checking the actual figure at the pin anyway. And the power is via an old laptop supply.

With my IV SE I don't need the socket extenders (thank God!) - I just remove all the brass bits...

 

And so at the moment, my rig is looking like this :

 

 

.....and sounding like...:gs1000smile:

 

 

 

Quote:
Originally Posted by gibosi View Post
 

 

Probably you would need two external power supplies.... The reason I say this is I haven't seen a cheap voltage regulator that I am confident is good for 5A. All those I have seen that are labeled 5A add something like "Recommended for use in the 4.5A". So I am not sure it is a good idea to try to draw 5A through one of the these.

 

Similarly, I have been thinking about running a Cetron JAN 6336B in my LD1+. However, this is a 5A tube. And I just don't know how to interpret "Output current: 0-5A. Recommended for use in the 4.5A."

 

 

Hi g,

 

As I mentioned above, I think I have found a regulator that can deliver, minus the readout that is.

 

As for the 6336B, have you checked ALL the tube data? I thought it was one mighty job to match OK....


Edited by hypnos1 - 5/9/14 at 1:11pm
post #6078 of 10502
Quote:
Originally Posted by hypnos1 View Post
 

 

Right then folks, here we go - at last! - the 6AS7G as power tube (only 1, in the right channel at the moment, with the Psvane CV181-T II in the left).

 

Well, all I can say at the moment is...WOW! I wasn't really expecting anything could outdo the TS 7N7 in my setup, but after about half an hour (I believe these tube types need a fair warm-up) I just could not believe it...initial impressions were greater dynamics, more detail especially in the upper bass/lower mids, and an even more expansive soundstage (assisted in my Clannad tracks by more of the reverb). A much more intensive listening appraisal will have to wait I'm afraid - peering into the MKIV SE's innards, while holding the temperature probe hard against the cathode resistor and watching the temp readout with much trepidation was NOT very conducive to proper sound assessment, lol!!

 

Anyway, much to my great relief the temperature didn't do heart-stopping jumps, but a gradual rise to 56/57C after an hour's continuous playing (the 6SN7-types held at 28C).

Better still, it stayed there after 2 hours; then just 58C at 3 hours, and 59C at 4 hours. As I believe this is way below the maximum rated temp for such a resistor, it looks as though we may be OK with these tubes after all...if so, I think this could  be just as  great a leap for our LDs (the MKIV SE, anyways) as was given by the C3g drivers. I am over the moon - at present at least! The prospect of BOTH RCAs up and running is getting me all of a lather:tongue_smile:.

 

As for setup, mordy, I am using a 6SN7 to 6C7G adapter, with pins 4 & 5 of the latter chopped off, all bar enough to solder the external heater wires (then covered with tape, of course).

I managed to find a voltage regulator rated at 8A, which at the moment with just 1 tube is working fine - no real heat from it even after 4 hours' use. It is on amazon.com for $10.96 (free shipping), and .co.uk for £4.99 (free UK shipping). It is listed as "Input AC/DC 12-45V to Output AC/DC 0.7-21V 8A converter board step-down voltage regulator module"... It has no readout, so you do need a meter, which is good for checking the actual figure at the pin anyway. And the power is via an old laptop supply.

With my IV SE I don't need the socket extenders (thank God!) - I just remove all the brass bits...

 

And so at the moment, my rig is looking like this :

 

 

.....and sounding like...:gs1000smile:

 

 

 

 

 

Hi g,

 

As I mentioned above, I think I have found a regulator that can deliver, minus the readout that is.

 

As for the 6336B, have you checked ALL the tube data? I thought it was one mighty job to match OK....

Finally that is what i been waiting for 6AS7 Power Tubes if only my 12A regulator is here danm speedboat.

post #6079 of 10502
Quote:
Originally Posted by hypnos1 View Post

 

As for the 6336B, have you checked ALL the tube data? I thought it was one mighty job to match OK....

 

Great work! So it does seem that the LD's can handle 6AS7-types with relative ease. :)

 

And yes indeed, the 6336B is quite a tube. Some have described it as equivalent to two 6AS7's in one bottle! While I have no real plans to run the 6336B in my LD, I wanted to make sure that I could provide 5A if I ever become crazy enough to try. lol :) 

post #6080 of 10502
Quote:
Originally Posted by i luvmusic 2 View Post
 

I'm  bidding on 3 RCA 6AS7G i hope i can get this one i really want this,preparing for my future CRACK not only that i can still use this tubes with my LD's.:ksc75smile:

Did they just sell for $26.00 if so i just won that auction sorry man 


Edited by MIKELAP - 5/9/14 at 5:37pm
post #6081 of 10502
Quote:
Originally Posted by MIKELAP View Post
 

Did they sell for $26.00

Don't tell me you got them yes they are.

post #6082 of 10502
Quote:
Originally Posted by i luvmusic 2 View Post
 

Don't tell me you got them yes they are.

Lol ill have to move i guess 

post #6083 of 10502
Quote:
Originally Posted by MIKELAP View Post
 

Did they just sell for $26.00 if so i just won that auction sorry man

No worries but if you want to sell one PM me thanks!

post #6084 of 10502
Quote:
Originally Posted by MIKELAP View Post
 

Lol ill have to move i guess

At one point during the auction i bet 28 then back it down to 24 then it's done.Lucky You!

post #6085 of 10502

I guess better luck next time:(

post #6086 of 10502
Quote:
Originally Posted by i luvmusic 2 View Post
 

At one point during the auction i bet 28 then back it down to 24 then it's done.Lucky You!

My maximum was $37.00

post #6087 of 10502
Quote:
Originally Posted by MIKELAP View Post
 

My maximum was $37.00

Will i did not go that high....

post #6088 of 10502

 Finally i received my 12A regulator last night and started using it with my desktop power supply(12V-15A)and 6AS7 power tubes for Ld MK III and i noticed a fire hazard.Cable 4feet 18awg stranded is not enough to supply 7V-6.2A(as per my crappy multi meter).The cable it gets very soft and hot it nearly  burnt on me luckily i  noticed the burning smell  and when i grabbed it man it's that hot then i replaced it with 16awg and it's fine now.The 12A regulator it gets really hot as well so my guess is i'am screwed for the other two 7.5A regulator that i ordered it looks like i can't used just one of those 7A regulator to supply 6AS7 Power tubes and 6SN7 driver tube.

 


Edited by i luvmusic 2 - 5/10/14 at 9:30am
post #6089 of 10502
Quote:
Originally Posted by i luvmusic 2 View Post
 

 Finally i received my 12A regulator last night and started using it with my desktop power supply(12V-15A)and 6AS7 power tubes for Ld MK III...

 

 

This is your LD MKIII? I think you have stuffed it into another enclosure? But in the picture, I am seeing 8 tubes!

post #6090 of 10502

No it's the LD 1 in the case the other tubes are for MK III as you can see in the picture i have the 6AS7 side by side that is the power tube  and on the right back  tube is the driver adapter for MK III on the left back tube is for the LD 1 and the front tubes are adapters for 12A.. 6DJ8 and driver tube for LD 1 because i can't access it anymore MK III is beside the adapter and i have a terminal block behind to connect what ever adapter i need  or which amp to connect it to.I was going to put the Mk III with the LD 1 but i don't have enough room in that chassis plus it's going to be a pain  in the butt for me to take these amps with me on my way back home.I don't know if i'am allowed to fly with these type of electronics or i just shipped them out back home.

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