• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Large triode for PP amp.

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
kodabmx

kodabmx

Member
Joined 2011
smoking-amp said:
4 x 12HL7 in parallel would give 357 Ohms Rp at 100 mA total in triode. (and 40 Watt Pdiss) And 84000 gm! (5.5V peak drive signal) Not -too- absurd actually. (that GMI-83V needs 400V pk drive !!! now that IS absurd)
Click to expand...

Reminds me of my Stupendous amp. 8x6P1P triode connected per channel. 3K RLa-a... 300V and 40ma per tube. Cleanest 15W amplifier on Earth for the money IMHO lol
 
Tubelab_com

Tubelab_com

Member
Joined 2005
tubelab.com
I built a push pull 300B amp about 10 years ago. It made 30 watts at about 400 volts into a 6600 ohm OPT. This means it would be possible to get 60 watts into 3300 ohms with a parallel push pull pair. I don't know your budget, but 8 X 300B's are NOT in mine.......

I have breadboarded a triode wired 6550 amp that ran an Edcor 3300 ohm 100 watt OPT and it made 75 watts. It can be seen under test here.

YouTube

And some details can be found here:

Tubelab Universal Driver Board, 2015 version
 
45

45

Member
Joined 2008
ArcheusLedoux said:
Oddly enough just got finished with a 300B quad. My friend David in ElPaso just finished up the last bit of it. here's a link YouTube In this thread I was looking for a large triode. Not a bank of 4 or 8 tubes. 304TL is one of the candidates.
Click to expand...

This will work nicely:

1605 tube data sheet, by Emission Labs.

but it's very expensive at $1254 per pair!!!

Otherwise you need to "compromise" with less linear devices, unusual items or paralleled tubes....and/or less power....
 
45

45

Member
Joined 2008
ArcheusLedoux said:
I can't find the Push Pull data for the 1605. They only show SE on the website.
Click to expand...

One can get a good estimate from the existing data. For sure it will double the SE power....at the very least 45W pure Class A. For practical class A (i.e. total r.m.s. current draw not exceeding quiescent current draw) it will be some 60W. 80-100W in class AB1 with very low distortion anyway as the tube has got good linearity.
 
45

45

Member
Joined 2008
Yes, they are expensive at $1250 per pair but at the same driving voltage and anode voltage is still in the (reasonable) 500-600V range. Basically the same power level of tubes like the 845 with halved plate voltage and (for sure) lower cost for the power supply. IMHO, one should consider the overall cost and size of the amplifier to make comparisons.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom