Hi, I am planning to build a PP amplifier with a global negative feedback. This is a general question: which tube would give the most musical sound?
Gain: let's say 20 dB
Required swing: let's say 15Vpp
Topology (driver stage): LTP ECC88 with 33k anode resistors
Output tubes: does it matter for the sound of the input tube? (BTW 807)
I lean towards the EF83 but waitig for experienced opinions.
Required swing: let's say 15Vpp
Topology (driver stage): LTP ECC88 with 33k anode resistors
Output tubes: does it matter for the sound of the input tube? (BTW 807)
I lean towards the EF83 but waitig for experienced opinions.
The EF83 is a variable gain (mu) pentode, usually use in constant level applications.
I'm not sure, that using as VAS stage it's the best choice.
The 180F is super VAS tube ... if you want single stage VAS and -relatively- large gain (about 45-50 as triode). I use it ... but prefer E280F or D3a.
GroupBuild Forum - 300B SE Project, Part 9 - E180F, E280F, D3a pentodes - triode connected - Damir, March 09, 2006 at 14:19:29
https://www.diyaudio.com/forums/tubes-valves/320418-45-amp-build-direct-coupled-3.html#post5383141
In your case (20dB gain, 7.5V peek) IMO none of them the perfect choice.
Try lower mu triodes.
I'm not sure, that using as VAS stage it's the best choice.
The 180F is super VAS tube ... if you want single stage VAS and -relatively- large gain (about 45-50 as triode). I use it ... but prefer E280F or D3a.
GroupBuild Forum - 300B SE Project, Part 9 - E180F, E280F, D3a pentodes - triode connected - Damir, March 09, 2006 at 14:19:29
https://www.diyaudio.com/forums/tubes-valves/320418-45-amp-build-direct-coupled-3.html#post5383141
In your case (20dB gain, 7.5V peek) IMO none of them the perfect choice.
Try lower mu triodes.
Last edited:
The E83F is not the special quality version of the EF83. They differ quit a bit from eachother. I don't think the E83F is a vari-mu tube.
Attention! E83F is not the EF83's SQ version! And it isn't a remote control tube either.
Best regards!
Best regards!
I am considering the option of triode connecting the input tube. The E180F datasheet gives parameters for triode connection, but the E83F does not.
Sample schematic attached.
Are you read this?
E83F - MV Audio Labs
..and see this..
Figure 1 from Minimum noise pre-amplifier for fast ionization chambers | Semantic Scholar
Are you read this?
E83F - MV Audio Labs
..and see this..
Figure 1 from Minimum noise pre-amplifier for fast ionization chambers | Semantic Scholar
Attachments
Last edited:
Two more examples: An amplifier and a microphone preamplifier, both using an E83F.
Addition: According to the attached page from VTV magazine no. 11 from 1999 the E180F is a frame grid tube.
Addition: According to the attached page from VTV magazine no. 11 from 1999 the E180F is a frame grid tube.
Last edited:
Agreed. In my preamp I prefer below tubes in sequence (all wired as triode):
1. E810F - hands down one of the best high bandwidth tube with ultra high Gm. Rich and full of dynamic punch but not fatigue.
2. E186F - on par with E280F in most cases. A bit more smooth than E280F.
3. E280F - balanced and great sound overall but not as that open as E810F.
4. E180F - high dynamic but sounds flat and just OK. A little bit thin on treble and lack of deep bass punch like above other pentodes.
Russian 6E5P triode-wired is a fantastic tube. Cheap, too!
That's what I use as the input tube in my Midlife Crisis 833C mono amps.
That's what I use as the input tube in my Midlife Crisis 833C mono amps.