I built an amp a while back for a customer. He had some money to throw around so we decided to have me build one of the "Old Flame" amp kits from Allen amplifiers. The amps are freakin awesome updated versions of fender amps and the kit comes with some top notch american made transformers as well as cool features like post phase inverter master volume circuits, his unique RAW control which is a midrange boost circuit, 3 knob reverb, external bias adjustment, speaker impedance switch, the ability to use 6L6 tubes or 6v6 tubes in the power section as well proper transformers to handle these voltages and different rectifier tubes. I could have built something similar from the ground up, but these kits have some amazing parts and I love the way the first preamp tube is located right next to the input. I also love how its a one channel amp- so I didnt have to fabricate a custom chassis or rig a standard chassis to accomodate the three knob reverb raw and master volume control. The cabinets David supplies are also killer.
The customer got a 1x15 speaker cabinet that he loaded with a JBL K130- with the amp built into a head cabinet. This allows a TON of variations from the same amp. With the ability to use his other speaker cabinets loaded with MUCH different speaker types (the JBL's are a breed of their own and make more of a difference in tone and volume than even different tubes!) switching from 6L6 tubes with the JBL to 6v6 tubes and say some inefficient old jensens or CTS speakers makes this amp a COMPLETELY different amp. I mean not even close. Along with the raw control and master volume you have options for every type of fender combo you could imagine, as well as a ton of non typical fender sounds with the master volume and the raw control.
Anyways- I customize the amp by using my own choices of component compositions and hand measuring and matching components to extremely tight tolerances. I used a combination of audio grade american made Dale RN70 metal film resistors where noise was important. In the audio path I used Japanese made audio grade Takman carbon film resistors. I changed the tone stack a bit to get a bit tighter bass using a .047uf capacitor for the bass tone stack cap and .022 for the mids. I used F&T electrolytics for the cathode bypass caps. I hand matched the phase inverter capacitors to be exactly the same. I also tested each film capacitor to find the lead connected to the outer layer of foil and oriented them 'correctly' this technique is something they used to do in the original fender amps. or tried to do, and it really lowers the noise to really add that extra magic of harmonic content available in the amp. this amp also features star grounding and thick solid core wire. It is a beast of an amp with all of the options you could possibly want.
The results of my component selections, matching and measuring gave me absolutely the quietest guitar amp i've ever played. It will actually startle you if you warm it up and turn it on and have the volume up high. When you pick up your guitar and go to hit a note it startles you with the volume, i never expect it to be THAT loud with how little hum is coming from the amp. Crazy.
Here's a terrible demo I recorded
Link to video demo of the amp
*it should be noted that this demo was recorded using modern production tubes. some tung sols or some other crappy modern tubes. This amp really came alive with a NOS 5751 in v1 and a NOS rca 12ax7 in the phase inverter and some NOS 6L6 power tubes
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