Compact ~20WPC Tube Amp

Hey guys, we all know that you both build great products. Deep respect for Atmasphere and Aric Audio.

Here's what we don't know...what speakers does the OP own, are they mechanically and electrically to spec and are they appropriate for a tube amp?

@mdalton 

Until the OP shares the specifics on his speakers, its all just conjecture. The Leben CS300xs is a really cool and versatile amp. It also has a switch for 4/6/8 ohm output impedence. 

Alot of solid recommendations and yet, not a mention of the speakers in question. The OP hasn’t mentioned what speakers he is using that are admittedly somewhere around 45-50 years old. He hasn’t mentiontioned impedence, brand, whether the crossovers have been updated to specification and whether the drivers are in proper working order. If it was my money, before I spent a dime on anything further, I would think it prudent to have the speakers tested by someone competent. It’s likely there is an amp/speaker mismatch but how do you know? And how can we make appropriate recommendations?

@dhcod

Are you going to share the specifics on your speakers? I’m a huge fan of the EL84 tube but depending on your speakers, they could be wrong. It also depends on the amp topology. A single ended el84 amp begins to distort at 5ish watts with max power 9-10 watts per channel. Push pull begins to distort around 6-9 watts and tops out around 12-15 wpc. Some of the old Scott’s that use the 7189 can be pushed a little further to achieve high teens realistically. I believe the EAR, quicksilver, Manley and some others use 8 rather than four el84’s so those numbers can double up.

Once again though, if you would share your speakers with us we might be able to provide better advice. 4ohm? All bets are off. Crossovers with 50 year old caps? Ditto.

@dhcod 

For the time being, I'm starting to play with a Scott 222C, also an EL84 amp @20WPC, just to confirm that more power is what I'm looking for. Seems to be so far.

Did you already own the 222c or were you able to find and purchase one that quickly? Please be very careful, the 222c is NOT an EL84 amplifier so if yours has EL84’s installed and hasn’t been modified that could be an interesting fireworks display to come. The 222c uses 7189’s or, in a pinch, the modern day close proximity, the EL84M has been used by some.  I wouldn’t but that’s me. Please be careful. Also, what kind of speakers are you running?