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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 313

post #4681 of 10506

I really like the US-made Raytheon 6CG7 too. :)

 

However, today, a 1961 Heerlen-made E80CC (VB8 delta1A1) arrived. As this tube is very similar to a 12AU7, I disconnected pins 8 and 9 on my 6DJ8-configured socket (if I left them connected, it buzzed), adjusted the heater voltage up to 12.6 and it sounds great!

post #4682 of 10506
Quote:
Originally Posted by gibosi View Post
 

I really like the US-made Raytheon 6CG7 too. :)

 

However, today, a 1961 Heerlen-made E80CC (VB8 delta1A1) arrived. As this tube is very similar to a 12AU7, I disconnected pins 8 and 9 on my 6DJ8-configured socket (if I left them connected, it buzzed), adjusted the heater voltage up to 12.6 and it sounds great!

You know your just enabling me...lol

 

I'll get to them when I get comfortable with these... I love how these sound... the massive, detailed sound stage... the great dynamics, and even with the extended treble they never sound harsh.

post #4683 of 10506
Quote:
Originally Posted by kvtaco17 View Post
 

You know your just enabling me...lol

 

I'm just doing my job! lol :)

post #4684 of 10506
Quote:
Originally Posted by gibosi View Post
 

I really like the US-made Raytheon 6CG7 too. :)

 

However, today, a 1961 Heerlen-made E80CC (VB8 delta1A1) arrived. As this tube is very similar to a 12AU7, I disconnected pins 8 and 9 on my 6DJ8-configured socket (if I left them connected, it buzzed), adjusted the heater voltage up to 12.6 and it sounds great!

 

Great work, gibosi! One more tube type tested on our LDs! I feel like I'm almost being left behind at this point lol, with my barely rigged MK IV that only has a 6DJ8 tube mounted on a basic adapter...

 

I wonder what David Zhezhe would think about all this lol... It really would be great if they came up with a MK III / IV that uses a single B9A tube as a driver; just to make it easier to adapt tubes...

post #4685 of 10506
Quote:
Originally Posted by Audiofanboy View Post
 

Great work, gibosi! One more tube type tested on our LDs!

 

It is really great to have a configurable socket and an external heater PS. The universe of possible tubes has grown much larger than before. But to be frank, I am feeling a bit overwhelmed with all the tubes I have, so will let this E80CC run for a few hours, just to make sure there is nothing wrong with it, and then will put it aside, along with the 6FW8, 7AF7 and the others. I think I need to stop buying new tubes for awhile and just work through this rather large pile that I have already accumulated. :)

 

For now, I want to get to know the Tung Sol RBP and the Sylvania Bad Boy better. After a only a few hours, both impress me as mighty fine tubes. So I want to take some time to become more familiar with their sound and then try to write up my impressions and observations.

 

Tubes (Click to show)
LL
post #4686 of 10506

http://www.duncanamps.com/tdslpe/

 

something we can use as a reference for pin compatible tubes...

post #4687 of 10506
Quote:
Originally Posted by gibosi View Post
 

However, today, a 1961 Heerlen-made E80CC (VB8 delta1A1) arrived. As this tube is very similar to a 12AU7, I disconnected pins 8 and 9 on my 6DJ8-configured socket (if I left them connected, it buzzed), adjusted the heater voltage up to 12.6 and it sounds great!

 

A picture... E80CC and E88CC, both Heerlen-made in 1961. The E80CC is tall!

 

post #4688 of 10506

Hi Gibosi and kvtaco17,

 

Having spent a little more time with the Japanese Raytheon 6GC7/6FQ7 I must say that it grows on you. After spending time listening to a 1953 Tung Sol 6SN7GTB tube you have to adjust to next tube type - it takes a little time to get a settled opinion. While the TS 6SN7 is more musical and has a round fat bass, the Jap Raytheon is more detailed with a gorgeous wide forward sound stage with a fantastic timbre and exquisite high end and clarity, although the bass is not as tactile. Both tubes are really excellent.

 

Again, these are early impressions, subject to change. But, the wow factor is there...Man, I just smelled the breath of the trumpet player I am listening to LOL!

 

 

 

Thanks to Oskari  (remember the mystery of Siemens Foreign tubes?) we now know that Raytheon had ties with Toshiba and that they used Philips sourced manufacturing equipment. The tube could also have been made by Hitachi.

 

Anyhow, I got this little bargain voltage regulator with a digital readout. There were many sellers of what looked like the same item, so I picked one seller of several who had the same low price of $4.33 incl. shipping. I picked a company with over 100.000 feedbacks and well rated. Unfortunately the shipping took a full 30 days, which I feel is too long. I have gotten stuff from China in 5 days, but usually it takes around 14 days. Maybe the end of year volume slows things down.

 

The voltage regulator is adjusted with a little brass screw, but I cannot adjust it exactly. Either I get 6.27V or 6.43V - nothing in between. Checking the voltage with my Sears multitester I get a readout of 6.30V when the voltage regulator reads 6.27V.

 

Which value should I trust? (The Sears tester is a cheap $20 unit)

 

Happy tube rolling!

post #4689 of 10506

Hi Gibosi,

 

When listening at normal levels I cannot hear much of buzzing or humming, but turning it up very load there is a buzzing and a background hum.

 

Grounding the voltage regulator took care of the buzzing, but the low level hum is still there. Could be from all the wires I have running to my receiver, because this hum is there when the Little Dot is shut off.

 

Are you suggesting that I disconnect the socket pin 8-9 loop using the 6DJ8 setup for the 6CG7/6FQ7 tube?

post #4690 of 10506
Quote:
Originally Posted by mordy View Post
 

Hi Gibosi,

 

When listening at normal levels I cannot hear much of buzzing or humming, but turning it up very load there is a buzzing and a background hum.

 

Grounding the voltage regulator took care of the buzzing, but the low level hum is still there. Could be from all the wires I have running to my receiver, because this hum is there when the Little Dot is shut off.

 

Are you suggesting that I disconnect the socket pin 8-9 loop using the 6DJ8 setup for the 6CG7/6FQ7 tube?

it very well could be caused by all of your wires everywhere... I have an identical setup except my wires are dressed in and they are in an enclosure... I have very little noise even when I have the volume up all the way with 32ohm cans.

 

I'd trust your multimeter vs the integrated one... I noticed about a 10th or so difference between the integrated one and my fluke. And FYI I still have 8-9 connected still.

 

I do agree that this tube does not have very weighty bass BUT it is more then enough for my tastes. It really is excellent in its timbre. I do love the high end detail and big sound stage, as well as the apparent quickness/clarity this tube posses.

post #4691 of 10506
Hey kvtaco17

A Fluke you say... very nice which model?
post #4692 of 10506
Quote:
Originally Posted by TrollDragon View Post

Hey kvtaco17

A Fluke you say... very nice which model?

I have 2 87's... one for work and a very old one with the old green LCD for personal use... they were both just calibrated courtesy of work lol

post #4693 of 10506

Hi kvtaco17,

 

"I do agree that this tube does not have very weighty bass BUT it is more then enough for my tastes. It really is excellent in its timbre. I do love the high end detail and big sound stage, as well as the apparent quickness/clarity this tube posses."

 

Spot on - exactly my impression! As I am listening I became more aware of the quickness and clarity, just like you say.  Another plus of this tube; it will take away the sibilance from a sibilant recording and make it more pleasurable to listen to.

 

I will go as far to say that this tube has the detail of a 6DJ8 and most of the warmth of a 6SN7 tube.

 

I have some RCA, GE and Sylvania 6CG76FQ7 tubes to test as well. We'll see who is the winner....

post #4694 of 10506
Quote:
Originally Posted by mordy View Post
 

When listening at normal levels I cannot hear much of buzzing or humming, but turning it up very load there is a buzzing and a background hum.

 

Grounding the voltage regulator took care of the buzzing, but the low level hum is still there. Could be from all the wires I have running to my receiver, because this hum is there when the Little Dot is shut off.

 

Are you suggesting that I disconnect the socket pin 8-9 loop using the 6DJ8 setup for the 6CG7/6FQ7 tube?

 

If the hum is there when the LD is off, then I doubt that it has anything to do with your LD. I strongly suspect that it is receiver related.

 

The only time I remove the connection between pins 8 and 9 is when I am running a 12A-7-type tube with 12.6 volt heaters. Some 6CG7/6FQ7 tubes have shields on pin 9 which should be connected to pin 8. In those tubes that don't have shields, pin 9 is not used (if you look at the base of the tube, you will see that pin 9 is open), so connecting pin 8 to pin 9 will make no difference. 

 

I have loctal and octal adapters with 6DJ8/6CG7 on the bottom and I have used 12 volt octals and loctals, 12SN7, 14N7 and 14AF7, with pins 8 and 9 connected and experienced no problems. After all, the octals and loctals have only 8 pins, so pin 9 is not used.

 

So if you are running a 12A-7-type tube at 12.6 volts in a socket configured for 6DJ8/6CG7, disconnect the shield. Otherwise, leave it connected.

post #4695 of 10506

Did not know that there is a market for empty tube boxes:

 

http://www.ebay.com/itm/NOS-MULLARD-EMPTY-TUBE-BOXES-for-ECC83-12AX7-or-E88CC-/230919170412?pt=Guitar_Accessories&hash=item35c3dae96c

 

What puzzles me is that there were 6 available and 4 sold.....$12 for an empty box?! Give me a break!  This must be a fluke!

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