King Tut Posted December 15, 2019 Posted December 15, 2019 I had a sneaking suspicion all was not as it seems, so I took the top off of my Bugera Veyron Tube and switched it on. So, it seems that the very lovely valvey glow that shines through the front of the amp isn't the valves glowing at all, but three orange Led's, cunningly set on a dimmer so they gradually fade in after you've turned the amp on. What's that all about then? I don't know much about valve amps - maybe someone could enlighten me as to why the actual valves dont glow? I can feel heat coming off them so they appear to be real and not just for show! Quote
wateroftyne Posted December 15, 2019 Posted December 15, 2019 (edited) It's pretty common practice. Preamp valves don't glow, 'cos there's not enough power involved. Power amp valves do. Edited December 15, 2019 by wateroftyne 3 Quote
King Tut Posted December 15, 2019 Author Posted December 15, 2019 4 minutes ago, wateroftyne said: It's pretty common practice. Preamp valves don't glow, 'cos there's not enough power involved. Power amp valves do. AHH thanks for that - interesting! Quote
Newfoundfreedom Posted December 15, 2019 Posted December 15, 2019 I could have saved you the bother of removing the lid. I've got the MOSFET version and it still has a red glow, so I was never under any illusion that it came from valves. It sure looks purdy though. 1 Quote
King Tut Posted December 15, 2019 Author Posted December 15, 2019 (edited) 1 minute ago, Newfoundfreedom said: I could have saved you the bother of removing the lid. I've got the MOSFET version and it still has a red glow, so I was never under any illusion that it came from valves. It sure looks purdy though. Hahaha that's funny, I thought only the valve one glowed! Edited December 15, 2019 by King Tut 1 Quote
thodrik Posted December 15, 2019 Posted December 15, 2019 EBS Fafner has a similar thing. The bulb keeps breaking. I am going to replace it with a blue bulb instead, so people will think that the pre-amp valve is really cold. 4 Quote
Sparky Mark Posted December 15, 2019 Posted December 15, 2019 I believe that particular amp is a GB Streamliner clone that had blue LEDs that shone through the oval window on the front panel. Unfortunately there were quite a few that stopped lighting up although the amp still worked fine. 2 Quote
Chienmortbb Posted December 19, 2019 Posted December 19, 2019 The only issue with The Veyron for me is too much light, although I can always find it when the stage lights dim. 1 Quote
Hellzero Posted December 19, 2019 Posted December 19, 2019 On 15/12/2019 at 20:45, wateroftyne said: It's pretty common practice. Preamp valves don't glow, 'cos there's not enough power involved. Power amp valves do. And I'm not sure there is 200 to 300 Volts to make them work properly... Here is the data sheet of a typical preamp valve (or tube), a 12AX7 aka ECC83 aka 7025 : 1 Quote
MacDaddy Posted December 19, 2019 Posted December 19, 2019 There was a Marshall valve bass head, and the valves were in a kind of cage, so you could see them glowing. Beautiful. Quote
Stub Mandrel Posted December 19, 2019 Posted December 19, 2019 I bought a twin valve preamp module, it has LEDs under the valve bases so they glow ... blue 🙂 Quote
songofthewind Posted December 19, 2019 Posted December 19, 2019 2 minutes ago, Stub Mandrel said: I bought a twin valve preamp module, it has LEDs under the valve bases so they glow ... blue 🙂 Ah, grasshopper, that is COLD FUSION. 1 Quote
Chienmortbb Posted December 20, 2019 Posted December 20, 2019 23 hours ago, Hellzero said: And I'm not sure there is 200 to 300 Volts to make them work properly... Here is the data sheet of a typical preamp valve (or tube), a 12AX7 aka ECC83 aka 7025 : Surely the glow comes from the heaters, not the amount of power being dissipated within the device? The last valve amp I had was fitted ECC83s and I am sure they glowed. Quote
bartelby Posted December 20, 2019 Posted December 20, 2019 The valves in my little Guyatone guitar combo glow nicely: 1 Quote
Hellzero Posted December 20, 2019 Posted December 20, 2019 27 minutes ago, Chienmortbb said: Surely the glow comes from the heaters, not the amount of power being dissipated within the device? The last valve amp I had was fitted ECC83s and I am sure they glowed. Indeed, they glow first because of the heater, then the electrons begin to flow from the cathode to the anode through the grid on a triode, but there must be enough tension at the anode to work properly otherwise you won't get the amplification expected (the gain) as the grid will block the flow of electrons. It's the simpliest way to explain how a triode works. Quote
songofthewind Posted December 20, 2019 Posted December 20, 2019 I fondly remember the warm orange-red glow of my Yamaha THR10. You could turn it off via software, but who would do such a thing?? Quote
stewblack Posted December 21, 2019 Posted December 21, 2019 I love the orange glow from my MOSFET Veyron. It's only window dressing but there's nothing wrong with that. Sounds pretty darned good too. Shoulder and back playing up so the Veyron is picking up a bit of work right now. Dare not risk the all valve or the Trace bi-amp with a dodgy back. 1 Quote
Newfoundfreedom Posted December 21, 2019 Posted December 21, 2019 4 hours ago, stewblack said: I love the orange glow from my MOSFET Veyron. It's only window dressing but there's nothing wrong with that. Sounds pretty darned good too. Shoulder and back playing up so the Veyron is picking up a bit of work right now. Dare not risk the all valve or the Trace bi-amp with a dodgy back. It's all I ever use. I still can't get over how good it sounds. 2 Quote
Stub Mandrel Posted December 21, 2019 Posted December 21, 2019 This has inspired me to order a strip of UV LEDs opf eBay from t Trace Elliot combo, which appears to have the fluorescent silk screening but no UV bulb. Will be fun if it works! 2 Quote
Woodinblack Posted December 21, 2019 Posted December 21, 2019 Orange leds are common, I have a Vox effects pedal with a valve and an orange led under it. It has nothing to do with how much power it is using, the heater of a valve works about 6v. Valves can be run without the heater, (cold plate), which is I assume what is done here. But as every fool knows, a valve that doesn't have an visible orange glow doesn't sound anywhere near as good! 1 Quote
Chienmortbb Posted December 21, 2019 Posted December 21, 2019 Does Valve Orange Glow create more heft than Orange Glow LEDs? 1 Quote
LukeFRC Posted December 21, 2019 Posted December 21, 2019 1 hour ago, Chienmortbb said: Does Valve Orange Glow create more heft than Orange Glow LEDs? not really, it doesn't matter what makes it: more glow = more heft 1 Quote
Stub Mandrel Posted December 21, 2019 Posted December 21, 2019 5 hours ago, Woodinblack said: It has nothing to do with how much power it is using, the heater of a valve works about 6v. Valves can be run without the heater, (cold plate), which is I assume what is done here. The applications of cold cathode devices are limited to low currents or those where heating is provided in other ways. I haven't come across cold cathode power amp valves. In some valves the heater is separate from and shielded by the cathode, that's probably the case in amps where they don't glow much. Quote
Woodinblack Posted December 21, 2019 Posted December 21, 2019 55 minutes ago, Stub Mandrel said: The applications of cold cathode devices are limited to low currents or those where heating is provided in other ways. I haven't come across cold cathode power amp valves. No - but the valves in the OP aren't power valves, they are preamp valves. Quote
Stub Mandrel Posted December 21, 2019 Posted December 21, 2019 8 minutes ago, Woodinblack said: No - but the valves in the OP aren't power valves, they are preamp valves. Even so... can you show me a link to a heaterless preamp valve? (I am willing to believe it if I see it!) 🙂 Quote
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