[Ultrainferno]

A completely different question: What's the longest time you've had the Bravo/indeed run in 1 stretch?
Would it hurt to keep it on from 8am to 5pm?
 
I know, just turn it of if it gets too hot

 

[sharkz]

I've had mine on for 4-6 hours a night the past few nights trying to burn in my new tube/headphones and the heatsinks get hotish to the touch, but if you give it a several minute break every few hours, it cools to near ambient temperatures very quickly. Just for the sake of curiousity, if I have time later I will get a reading off the heat sink with my IR thermometer after several hours of play. Should be interesting to see a temperature at that point and how quickly it cools again.

 

[zest]

Quote:

According to the measurements, these amps are supposed to sound like crap, but they don't. Screw the numbers... how does it sound? Oh yeah, post a picture of your 6n23p-ev. There are recently made garbage tubes out there with bright blue and bright yellow markings. Some folks are painting the nipples on tubes and claiming that this signifies that the tubes are special.
 
One last thing, the 6n23p-ev isn't an E88CC and won't ever be. That's a marketing scheme to imply that the tube is a high quality tube. The E88CC is a European only designation that is only comparable to the American 6922 designation. Russian tubes (and Chinese) never followed these standards. If you are dealing with Russian or Chinese tubes, always check that the tube specifications closely correspond to what you really need in the circuit. The tube specs of the 6n23p (and ev) place it within the 6dj8 family specs and is therefore equivalent. But it isn't an E88CC any more than a Chinese 6n11J is.

The best 6n23p-ev tubes are those that passed military tests, they are marked OTK like these:
 

 
and manufactured in Voshkod factory, they seem to be a bit better than the Reflectors tubes.
 


 
The specs of 6n23p-ev are close to E188CC, limited operating values are similar, e=long life (>5000hrs) and v=improved mechanics, I've read RCA sold some of them as 7308.

 

[zest]

Quote:

A completely different question: What's the longest time you've had the Bravo/indeed run in 1 stretch?

3 hours, I was reading a book, the heatsinks were pretty hot, but not more than after 30 mns of use.
 

 

[QuantumCarrot]

I've let mine run overnight a few times without problems.

 

[jjmai]

Why do these tubes glow blue?
Is there a blue LED in there, or is it just the gas in the tube lighting up?
But according to wikipedia http://en.wikipedia.org/wiki/Vacuum_tube, that's actually bad quality: "A tube with very bad internal gas may have a visible blue glow when plate voltage is applied."

 

[Ultrainferno]

It's just a blue LED under the tube

 

[sharkz]

I am pretty happy with my Reflector, it was $9 shipped. I need to rebias tonight so I am equal in both channels. I am sure it needs to burn in more too.
 
I am just disappointed I can't switch tubes more easily (without rebiasing). I would really like to A/B my tubes but it is a lot of work and harder to do than just swapping back and forth. It is hard for me to get a clear picture of how different the two main tubes (Jan Sylvania and Relfector) without hearing them next to each other. I need to spend some time "critically" listening in the future to figure out the sonic differences. Plus right now, I think my Fostex's are still settling in too.

 

[sharkz]

Just for the sake of curiousity, after about 4 hours playing, my amp is running at ~170F at the heatsinks and ~140F at the exposed portion of the tube. I would imagine it will cool right down with no load being applied to it.
 
Biased my tubes to exactly 15V each, now to do some more listening.

 

[Judge Buff]

Quote:

A completely different question: What's the longest time you've had the Bravo/indeed run in 1 stretch?
Would it hurt to keep it on from 8am to 5pm?
 
I know, just turn it of if it gets too hot

A couple of days... Don't worry about it.
 

 

 

 
and manufactured in Voshkod factory, they seem to be a bit better than the Reflectors tubes.
 
Rocket tubes rock! I have a 6n23p from 84 that is very nice! The best 6n23p that I have though is a 78 Reflektor ev. I also have a 69 Reflektor ev that isn't balanced.
The tube in your photo is much newer than even the 84 that I have. This decade or the 1990s?
 


 
The specs of 6n23p-ev are close to E188CC, limited operating values are similar, e=long life (>5000hrs) and v=improved mechanics, I've read RCA sold some of them as 7308.
 
I can believe that a valve of the quality of my 78ev would pass as a later 7308. It does sound as quiet as as clear as my E188CC Mullard, though the Mully is warmer sonically, and it sounds better to me than the 4 Sylvania 7308s that I have that are branded as Siemens. I consider the 78ev in my top 5 best tubes and the 84 6n23p in my top 25.
 
Once again, though, I say to beware of Russian tubes (and any Eastern European tubes) with bright blue or yellow markings. The OTK labels on my tubes are aged appropriately. It's too easy to stencil something on a tube that signifies that it is special, and Eastern Europe is rife with tube counterfeiters. Caveat Emptor! I think that any 6n23p valves that I get in the future will come out of Vladivostok...

 

[zest]

Quote:

The tube in your photo is much newer than even the 84 that I have. This decade or the 1990s?
 
I don't know, this seller don't mention the year.
 
I can believe that a valve of the quality of my 78ev would pass as a later 7308. It does sound as quiet as as clear as my E188CC Mullard, though the Mully is warmer sonically, and it sounds better to me than the 4 Sylvania 7308s that I have that are branded as Siemens. I consider the 78ev in my top 5 best tubes and the 84 6n23p in my top 25.
 
Once again, though, I say to beware of Russian tubes (and any Eastern European tubes) with bright blue or yellow markings. The OTK labels on my tubes are aged appropriately. It's too easy to stencil something on a tube that signifies that it is special, and Eastern Europe is rife with tube counterfeiters. Caveat Emptor! I think that any 6n23p valves that I get in the future will come out of Vladivostok...

The best offer I found is a Reflektor ev OTK tube from 1992, tested by the russian seller, for 15$+free shipping. The differences with E188CC/7308 are minimal from what I read, slightly less extended in lows and no golden pins, but I don't think this tube from 92 can compete with RTC E188CC from 79.

 

[jjmai]

Has anyone bought the amp from AmpPuzzles from ebay?  (They apparently have spammed some ads here and there before.)
Their design is more similar to Indeed G2.  Wonder how reliable they are....

 

[SuperF]

So after sitting in customs for 3 weeks the Muse version (uses 6n11 tube) of this amp finally made it to my door and BAH DOA. Im using a 24v 1.5a adapter (hp laptop) blue led is good and the heater in the tube glows except the red LED does not light. There is an oscillating hum that doesnt get softer or louder with volume and if I crank it full blast I can here the music but not much. The heatsinks get hot as well which of course is normal. Just seems to be something with the red LED. I understand it acts as a resistor of sorts. Any thoughts. Gonna jump back in this thread and see if anyone else had similar issues.
 
I do have a multimeter but im amateur at best when it comes to this stuff.
 
I dont want to bother with the hassle of sending it back since it will probably be another 3 months before I see it again. Sucks but thats life on ebay i guess.

 

[Avro_Arrow]

The red LED is part of the circuit that biases the tube.
A bad LED would definitely cause the amp to stop working.
Check the voltage drop across the LED (measure the voltage
by putting one lead on one side of the LED and the other lead
on the other side of the LED with power on). It should be something
like 1.8 volts. If it is 0 then the LED is shorted. If it's something like
20 volts, then the LED is open. Being shorted is the most likely problem.
Also check for bad solder joints on the underside. If possible, get a
good, clear picture of the underside.
The adapter you are using is fine.
 
Quote:

So after sitting in customs for 3 weeks the Muse version (uses 6n11 tube) of this amp finally made it to my door and BAH DOA. Im using a 24v 1.5a adapter (hp laptop) blue led is good and the heater in the tube glows except the red LED does not light. There is an oscillating hum that doesnt get softer or louder with volume and if I crank it full blast I can here the music but not much. The heatsinks get hot as well which of course is normal. Just seems to be something with the red LED. I understand it acts as a resistor of sorts. Any thoughts. Gonna jump back in this thread and see if anyone else had similar issues.
 
I do have a multimeter but im amateur at best when it comes to this stuff.
 
I dont want to bother with the hassle of sending it back since it will probably be another 3 months before I see it again. Sucks but thats life on ebay i guess.

 

[SuperF]

Great thanks for this I will check it this week. I checked for solder bridges or bad solder joints and all looks well. Ill still take a pic though when I have it apart.
 
Love the name by the way. Great moments in canadian history.
 
EDIT: Oh i can replace the LED with a resitor if its bad right. Anyone know what value of resitor im looking at?
Quote:

The red LED is part of the circuit that biases the tube.
A bad LED would definitely cause the amp to stop working.
Check the voltage drop across the LED (measure the voltage
by putting one lead on one side of the LED and the other lead
on the other side of the LED with power on). It should be something
like 1.8 volts. If it is 0 then the LED is shorted. If it's something like
20 volts, then the LED is open. Being shorted is the most likely problem.
Also check for bad solder joints on the underside. If possible, get a
good, clear picture of the underside.
The adapter you are using is fine.
 
Quote:

So after sitting in customs for 3 weeks the Muse version (uses 6n11 tube) of this amp finally made it to my door and BAH DOA. Im using a 24v 1.5a adapter (hp laptop) blue led is good and the heater in the tube glows except the red LED does not light. There is an oscillating hum that doesnt get softer or louder with volume and if I crank it full blast I can here the music but not much. The heatsinks get hot as well which of course is normal. Just seems to be something with the red LED. I understand it acts as a resistor of sorts. Any thoughts. Gonna jump back in this thread and see if anyone else had similar issues.
 
I do have a multimeter but im amateur at best when it comes to this stuff.
 
I dont want to bother with the hassle of sending it back since it will probably be another 3 months before I see it again. Sucks but thats life on ebay i guess.