ThermalAlchemy
New Head-Fier
I'm new to tubes and headphone amps, I missed the MassDrop 6XX (Sennheiser 650) buy, out here in the west cost it started at 6am. I'm building my first tube amp( The Starving Student Millett Hybrid). So I bought the DV 336se to compare as a bench mark, to my tube amp I built, to compare it to a mass production unit.
To start I read the tubes that come with the DV are no good (not so good, true) ,I just found Head-Fi recently and read everything I could about the DV. so i'm not disappointed. Yes they had a little hum in one side, No smoke when I first fired it up. I put a WATT meter on it. The draw was 53 WATTs. I let the tubes burn in for 48 hr. Still had a little hum in one side. On the 3rd day when i turned it on, no sound.
I'm taking a electronics class at a collage, and it just so happens they had a TV and radio repair class years ago and they are just going to dump the boxes and boxes of NOS tubes. All different makes, brands , numbers, from the 40s to the 60s. Lots of US NAVY and US ARMY 1941-1945 WWII still in the new boxes with yellow brittle plastic around them never opened. I jumped on Head-Fi forms about tube rolling ( i never heard of this term or knew nothing about tube until a few weeks ago) I googled and Youtubed about tubes for 24 hours crash course. I now have more tubes then i have hours of life left to listen to them all.
OK , so I replaced the Chinese 6AS7 with a NOS (GB 6080 SYLVANIA GOLD BRAND) and the DV worked. The Chinese tube that went bad had the numbers (83.11 J) and (6N5PJ) printed on it. I replaced the the Chinese 6SN7 (6N9or8P can't read clear and 84 8 T) with a NOS ( GB-6SN7 WGT SYLVANIA GOLD BRAND) WOW now it sound good, higher volume, lower lows, higher highs brighter tighter, better vocals now draws 60 watts of power. At first I thought my AMP was broken. Dead silent, no sound at all, no hum or buzz, no micrphonics when tapping on the tubes, absolutely nothing. turned on music "so much better", NOW MY DV was worth the $199. + shipping I guess.
i googled tube data sheet, info not to useful to me. The tube pin numbers and voltages did not quite match what i found and im not sure what should be AC or DC voltage at what pins. I did my voltage readings a follows. I took both AC reading and DC readings. From ground to pins.
DC VOLTS FIRST pin1 grid 0V, pin2 plate 0v, pin3 cathode 0V, pin4 grid 218V, pin5 plate 110V, pin6 cathode 0V, pin7 heater 218V, pin8 heater 111V
AC volt pin test. pin 1 grid 0V, pin2 plate 6V, pin3 cathode 0, pin4 grid 481V, pin5 plate 240V, pin6 cathode 0V, pin7 481V, pin8 111V
Question, someone with knowledge of the 6AS7 should I take pin to pin voltage reading? and what should they be if needed?. I'm a little worried about damaging my NOS tubes now. I have a LAB Scope but have no idea what I should look for on a tube
After reading about all the MODs to preform to the DarkVoice and additions sounds like everything gets replaced with better stuff. I might-as-well just build a new DV from scratch, from the ground up and hear what the differences is.
PS, having fun building my first Tube AMP the (SSMH) I pland to build the other SSMH AMPs to help build up my level to tackle more complex high voltage AMPS. @ http://www.diyforums.org/ and http://beezar.com/catalog/index.php
To start I read the tubes that come with the DV are no good (not so good, true) ,I just found Head-Fi recently and read everything I could about the DV. so i'm not disappointed. Yes they had a little hum in one side, No smoke when I first fired it up. I put a WATT meter on it. The draw was 53 WATTs. I let the tubes burn in for 48 hr. Still had a little hum in one side. On the 3rd day when i turned it on, no sound.
I'm taking a electronics class at a collage, and it just so happens they had a TV and radio repair class years ago and they are just going to dump the boxes and boxes of NOS tubes. All different makes, brands , numbers, from the 40s to the 60s. Lots of US NAVY and US ARMY 1941-1945 WWII still in the new boxes with yellow brittle plastic around them never opened. I jumped on Head-Fi forms about tube rolling ( i never heard of this term or knew nothing about tube until a few weeks ago) I googled and Youtubed about tubes for 24 hours crash course. I now have more tubes then i have hours of life left to listen to them all.
OK , so I replaced the Chinese 6AS7 with a NOS (GB 6080 SYLVANIA GOLD BRAND) and the DV worked. The Chinese tube that went bad had the numbers (83.11 J) and (6N5PJ) printed on it. I replaced the the Chinese 6SN7 (6N9or8P can't read clear and 84 8 T) with a NOS ( GB-6SN7 WGT SYLVANIA GOLD BRAND) WOW now it sound good, higher volume, lower lows, higher highs brighter tighter, better vocals now draws 60 watts of power. At first I thought my AMP was broken. Dead silent, no sound at all, no hum or buzz, no micrphonics when tapping on the tubes, absolutely nothing. turned on music "so much better", NOW MY DV was worth the $199. + shipping I guess.
i googled tube data sheet, info not to useful to me. The tube pin numbers and voltages did not quite match what i found and im not sure what should be AC or DC voltage at what pins. I did my voltage readings a follows. I took both AC reading and DC readings. From ground to pins.
DC VOLTS FIRST pin1 grid 0V, pin2 plate 0v, pin3 cathode 0V, pin4 grid 218V, pin5 plate 110V, pin6 cathode 0V, pin7 heater 218V, pin8 heater 111V
AC volt pin test. pin 1 grid 0V, pin2 plate 6V, pin3 cathode 0, pin4 grid 481V, pin5 plate 240V, pin6 cathode 0V, pin7 481V, pin8 111V
Question, someone with knowledge of the 6AS7 should I take pin to pin voltage reading? and what should they be if needed?. I'm a little worried about damaging my NOS tubes now. I have a LAB Scope but have no idea what I should look for on a tube
After reading about all the MODs to preform to the DarkVoice and additions sounds like everything gets replaced with better stuff. I might-as-well just build a new DV from scratch, from the ground up and hear what the differences is.
PS, having fun building my first Tube AMP the (SSMH) I pland to build the other SSMH AMPs to help build up my level to tackle more complex high voltage AMPS. @ http://www.diyforums.org/ and http://beezar.com/catalog/index.php
