TRIODE LAB

AP-AMERICANO Line-Stage Tube Preamp

Debut 2024

Derived from our original Au Pre Line-Stage Preamp which uses a pair of 12AU7 , but AP Americano uses a pair of 12AT7 instead , and same as the original Au Pre (AP here and after), which is a classical tube preamp design that is in-phase and pure analog. Quiet, wide-band, authentic sound / true to the source, good tube signature, realistic , and neutral is what we designed the AP-Americano to do.

WIMA (Germany) Coupling Caps is used as they are so accurate and balanced - what tubes you used will bring out exactly what the 12AT7 of that brand sounds like or intended to voice to. If we used the typical famous names of coupling caps - which they all have their own signature, then it could override the intended sound of the 12AT7 you used on the preamp. Look how much coupling caps we use in just one channel - there is no hold barred / or cost saving done - normally everyone just use 2 coupling caps here and look how many we used. And each pair of resistors on both channels are hand-matched / balanced. Both spec / sound is also reference level - don’t let the introductory price fool you, this is our latest preamp design, loaded with a few decades of our technique and experience in high end tube circuits. (And look at each single wires we used - it’s all sough thru and using the best sounding proper wires and materials used at each location, we don’t just randomly using this wire/cable because we sell them or have higher margins. And some tip for those who is interested is amp building - we never 90 degree band our signal path wires for a good reason).

The setting and values of the circuit is also intended for tube amplifiers - not of matching solid state gears (which has a lot design differences / almost opposite in many values and settings) - so most tube preamps on the market wasn’t really for the best sound of tubes, the mark is totally missed because most of them are really engineered for high power and solid state power amps. In another word - those who use a typical hifi branded preamp for S.E.T power amps - they probably aren’t listening the beauty of triodes or even close, and ruined the idea in going “SET”. A sample case would be even having the priciest Big Mac flagship preamp - it will just turned your SET system to sounded just like another “Mac” system. So no… probably alot or most people haven’t seen the true beauty of Single Ended Triodes - gone thru alot of gears? Yes perhaps. It’s like how CD Player were dismissed - almost 99.99% of people never saw the full potential because they never had a good player first place (like who invest that much on a disc player?), and never had good enough amps to show them, but most already thought they ’ve een there, done that. And Yes, we still like CD music and players so much.

12AT7 is often overlooked compared to it’s more famous siblings - 12AX7 (with a gain factor of 100) and 12AU7 (gain factor of 20), and 60 for the 12AT7. But some things the 12AT7 is actually even better - it’s actually more powerful than 12AX7 in FM receptions for example. And although with lower gain factor than the 12AX7 - the music has more headroom and arguable warmer and more musical, also more natural. And of course it has more gain and volume than the 12AU7. The AP Americano also feature the same high quality power supply like our current AP-EVO , which is proven quiet , reliable, and highly sound tune-able thru different regulate tube and rectifier tube, we also used a choke loaded power supply for quietest operation. Again, no cost is saved - we are just aiming the best approach on every single play of our design. Most tube preamps on the market just give you a simple / straight forward power supply formula - which works, and reliable enough like a Toyota. But at this price point, I think we should give a higher engineering to customers - which are often the more experienced bunch of audiophilers around the world, whom are usually having higher standards much like drivers of the Porsche-iest, who knows exactly what they are doing with their high quality audio system. And they know what to expect and hear too.

And there are also lots of hi quality replacement tubes that are designed for hifi / audio applications for 12AT7. Here is a few websites with more info , history and subs for this brilliant preamp tube that many forgets (that is why there are many good NOS of them, and at a much lower price than the other two). No, it doesn’t have to be matched - our feedback system on the circuit will balance out nicely, but make sure uses the same tube from the same lot/date (so if it comes in another brand or date code, it’s not). And for those who is interested which tubes we used to voice this preamp. It was the NOS Mullard 12AT7/ECC81/CV4024 - which we always craved for its sound signature. Then we always used something from Japan for comparison, which usually gives a totally different perspective. And for modern tube for testing - we selected the Psvane 12AT7S Gold Pins.

https://wallofsound.ca/audioreviews/tubes/a-mini-review-of-three-12at7-tubes/

by Wall of Sound

https://www.effectrode.com/knowledge-base/the-12at7-tube/

by Effectrode

https://jaazz.me/2019/01/04/12ax7-12at7-12au7-preamp-tubes-differences-explained/

by Jaazz.me

SPECS:

• Gain - 8X (Closer to 9X)

• 2V/RMS Nominal Output

• THD+N Less than 0.1% (We actually measured 0.044% only, a even lower figure, but we like to be conservative/humble with our numbers)

• Line amp S/N ratio : Better to 90dB

• Line input impedance : 80Kohm

• Phono amp gain : 90X/39dB @47K Input impedance

• Output Impedance : Less than 10K Ohms ( Different brand or different age of tubes will change the impedance : New tubes will have lower impedance and vice versa older tubes will have higher)

• Frequency response : Hi level /Line amp section :+/- 0.5dB at 20 to 20KHz

  Power consumption…115-120v ,50-60Hz , 40w Approm

• 12AT7 or equivalent Pair

• 12BH7 x 1 (tube regulation)

• 5AR4/GZ34 Rectifier Tube x 1 (rectifier stage)

• Hammonds Canada Power Transformer + Choke Transformer

• Volume Pot by Alps Japan

• Selector Switch by Lorlin UK

• Triode Lab Aluminum Black Anodized Knobs

• CMC USA Gold Plated Audiophile RCA Connectors

• Furutech Japan AC Inlet IEC Socket

• 1877 Phono Canada Gold Plated Ground post ($500 Optional Phono Stage)

MSRP $3,999 USD