all tube practice rig / guitar amp recommendations?

[jnewmark]

If you like the Ampeg 20-T, why not get the hum fixed? There is a thread here about the hum, which was common in these heads, and how to fix it. I think turning any electrical device on and off 20 times a day is probably not good for the device, whether tube or solid state, but I'm not an amp guru by any stretch.

 

[turf3]

Tubes require considerable current to keep the emitters up to operating temperature, whether there's any signal being amplified or not. Transistors don't.

There's some power draw in a transistor amp from the power supply(ies) at idle, but it's probably not much.

Put a clamp meter on it and find out.

That "200W" is the purported output to a speaker, NOT the power draw of the amp itself, and certainly NOT the power draw at idle. My uneducated guess would be that idle-condition power draw is something like 30W or so - 0.3A maybe. 8 hours x 30W = 240 Wh or 0.24 kWH. In my area electricity runs about $0.15/kWh so your one day's usage would cost you $0.045. (The above 30W is just my guess.)

 

[turf3]

I think anyone who's proposing to get up close with current measurements should consider owning one of these. I have found it invaluable.

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[agedhorse]

The idle power loss of a solid state amp will be in the range of 5-15 watts, the idle losses of even the smallest tube amp (like the PF-20) wound be 30-40 watts.

Just leave the solid state amp on and enjoy it. You are overthinking the problem IMO.

 

[agedhorse]

I think anyone who's proposing to get up close with current measurements should consider owning one of these. I have found it invaluable.

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Note that current measurements are essentially meaningless because an unloaded transformer is an almost purely reactive load and since power is the product of voltage x current x cosine of the phase angle between voltage and current. You can measure current yet have less real power than you think because apparent power (V x I =VA) rather than real (V x I x cos phase angle = watts) power.

 

[badinage]

To me, a formal bedroom (or classy office) rig should have iconic sonic and visual character, ...and a big flat top.

All that other stuff is conformist in an Emerson kind of way.

 

[Slidlow]

All you need is a tube amp with standby switch. Turns off the high voltage to the output but keeps everything else on idling.

 

[meisi]

To me, a formal bedroom (or classy office) rig should have iconic sonic and visual character, ...and a big flat top.

All that other stuff is conformist in an Emerson kind of way.

View attachment 7123238

We need a show us your living spaces rig thread.

 

[turf3]

Note that current measurements are essentially meaningless because an unloaded transformer is an almost purely reactive load and since power is the product of voltage x current x cosine of the phase angle between voltage and current. You can measure current yet have less real power than you think because apparent power (V x I =VA) rather than real (V x I x cos phase angle = watts) power.

Not meaningless, but you're correct of course that you can't get correct power by VI. However, true power meters that will deal with out of phase current/voltage are far more expensive than the elcheapo thingies that you plug into the wall. Since cos (phi) is always less than or equal to 1, calculating VA will overestimate power draw. In the case we're talking about here, where the thing MIGHT draw 20-30W, a VA calculation from a clamp meter is good enough to demonstrate that the OP is worrying about a big bunch of nothing.

 

[Plain Old Barry]

Yeah, draw as opposed to what is utilized or how much it takes to get to "200w" can vary a lot, I'd imagine amp topology plays a big role in that too. Might be worth it to grab a Kill-A-Watt (or competing brand) meter to see what actual draw is. If you don't have one already, this is a handy tool for many different applications.

Beat me to it...

They're ~ $30-35 at Harbor Freight or Amazon.

 

[logdrum]

If money is not an issue -- get a Fryette Power Station 50w and a all tube preamp like a Demeter, Frenzel, Jules , Sarno, Sushi Box or Alembic. The power station also works as an attenuator

I have a Frenzel that works great as a guitar and bass amp. I just flip the Frenzel deep switch, EQ adjust when I am playing bass. I also have a Demeter pre VTB-201 bass preamp. Sucks as a guitar pre-amp - awesome as a bass pre-amp. I also use solid state preamps.

The Fryette can be ran all day and I just flip it to standby

 

[agedhorse]

Not meaningless, but you're correct of course that you can't get correct power by VI. However, true power meters that will deal with out of phase current/voltage are far more expensive than the elcheapo thingies that you plug into the wall. Since cos (phi) is always less than or equal to 1, calculating VA will overestimate power draw. In the case we're talking about here, where the thing MIGHT draw 20-30W, a VA calculation from a clamp meter is good enough to demonstrate that the OP is worrying about a big bunch of nothing.

Yet for comparing the two numbers, it’s easy to end up making incorrect conclusions.

I deal with transformer design where we have to quantify these numbers and you can have a two transformers with the same 100mA unloaded current draw yet in terms of real power one transformer will have much lower real losses and thus a lower idle temperature. Of course there are other losses (hysteresis, eddy currents), etc. but ultimately they are all internet-related.

Since the OP’s concerned with cost, real power (VAR) is more important that VA.

I posted this info for folks who are interested and want to learn a little more.

 

[bherman]

I'm in the camp of keep using the combo - as @agedhorse points out, its electric usage is low - or any other low cost combo. For playing in 1-5 minute bursts, tube amps, preamps, etc are really not needed (IMHO)

 

[mauerkraut_]

Check out the Ashdown LB-30, CTM-30 or CTM-15. All tube power and preamp sections.

I practice with a preamp out into a cab sim with headphones. Quiet and doesn’t require power amp section.

 

[Matt Dean]

Pair a (used) Mesa/Boogie D-350 with the Bareface 10. That comber would be most killer...

 

[Wasnex]

If saving energy is a concern, stay with solid state.

The amount of current most amps pull at idles is usually less than they pull pushed to full power. Let's keep in mind this amp is 200W at 4 ohms and 150W at 8 ohms. Power specs for the TE ELF (from the OM).

Power Consumption: Typical = 30W Maximum = 240W

The power at idle is probably <30W.

I believe the impedance of the cab will impact how much power is drawn when the amp is pushed to it's limit. But it doesn't impact how much power is pulled at idle.

Here is the idle current and VA for some of my 200W tube amps (see note in italics below):

• Hiwatt DR201 = 1.57A, 188.4VA
• Mesa Buster = 1.97A, 236.4VA
• Mesa D180 = 2.05A, 246VA
• Mesa 400= 1.8, 216VA
• Orange AD200 Mk III 1.13A, 135.6VA
• Sadowsky SA200 = 1.86A, 223.2VA
• Sadowsky SA200 = 1.97A, 236.4VA
• Aguilar DB359 = 1.79, 214.8VA
• Matchless Thunderchief = 2.28A, 273.6VA

All of these amps pull more current as output power increases.

Power = Volts x Amps. VA also = Volts x Amps. VA is apparent power and Watts is actual power. AFAIK there's a difference with AC because the voltage and current waveforms will not be perfectly phase aligned. So actual power will be a bit smaller than VA. To calculate the difference you need to know the phase angle between the voltage and current.

 

[agedhorse]

The real power can be very different than apparent power on an unloaded transformer as the phase angle approaches 90 degrees, the cosine approaches zero.

On a solid state amp, at idle the power transformer phase angle will be pretty close to 90 degrees, but on a tube amp (due to static circuit losses) the phase angle will be quite a bit farther from 90 degrees to support the static load.

Also, this is how electric motors operate from unloaded to fully loaded the phase angle moves from ~90 degrees to ~0 degrees.

 

[Wasnex]

Here is the idle current and VA for some of my smallest tube amps:

• Fender brownface Princeton = 0.51A, 61.2VA
• Ashdown LB30 Mk1 = 0.92A, 110.4VA
• Ashdown LB30 Mk2 = 0.84A, 100.8VA
• Ashdown CTM 30 Little Stubby = 1.04A, 124.8VA
• Vox JMI era AC30 = 1.1A, 121VA*
• Ampeg PF50T = 0.86A, 103.2VA

* I run the AC30 on a variac at 110V

All of the Ashdowns and the Vox are cathode biased and run the output tubes at about 90% dissipation. I think they would probably eat tubes pretty fast if they were run all day. Also, urban legends says cathode biased output sections run hotter when the amp is idling than when the amp is pushed to the limit. I have done experiments that suggest this is true. Turning these amps on and off 20 times a day would also cause excess wear. I would say these amps are not suitable, given how the OP's intended usage.

 

[LowendG]

To me, a formal bedroom (or classy office) rig should have iconic sonic and visual character, ...and a big flat top.

All that other stuff is conformist in an Emerson kind of way.

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Love it. You need a Lava Lamp on top of that!

 

[murphy]

I have this little guitar combo...sounds great and janky with guitar, but very nice as a bass amp, especially running into a bass cab jamming at home...It was cheap