Silverface Bassman 50 Overhaul
We can get your silverface Bassman sounding and performing better than it ever has. As part of the standard maintenance/tune-up service, we clean all pots, jacks & switches, clean & re-tension all tube sockets, test all tubes, bias power tubes, tighten all pots, jacks, switches & transformers, and give the entire circuit an exam.
A full electrolytic recap is often required in original amps.
If you have a stock silverface, we HIGHLY recommend a signal cap upgrade. It’s like taking a wet blanket off of your speaker cab. This upgrade brings you closer to the blackface sound as much as the blackface mod does! It ‘opens up’ the amp considerably, giving you richer clean tone, smoother distortion, more clean sustain, improved touch sensitivity, and a more ‘musical’ sound in general.
The Mallory M150s are a big improvement over the stock signal caps. The Jupiter “Vintage Tone” series rolled mylar/foil caps are absolutely amazing, and very close both in tone and performance to the classic “Blue Molded” signal caps found in the original Blackface amps.
The blue ‘molded’ signal caps are some of the best caps ever made, regarding tone, performance, and longevity! If your amp is a late ‘60s AB165 and happens to have these blues, we keep them in!
As part of the service we dial in the circuit (called blueprinting) – certain key components are replaced if out of spec.
Shop rates are $90/hour plus parts. A typical complete blackface overhaul takes about 2 hours, and tends to average around $350 – $500 for the full treatment, depending on selection of certain components – NOS or new production carbon comp resistors, tube condition, etc. This estimate allows a new preamp tube or two, but does not include the price of a full re-tube if needed or desired.
We replace certain resistors that do get noisy over time such as the plate resistors in the preamp, bias board resistor, and power drop resistors in the power supply.
If you choose to keep your bassman circuit dead stock, we are more than happy to oblige! However, there are some folks who like to get a little more variety from their basman amp. Again we are happy to oblige! These are minor mods, easily reversible if you ever want to return the amp to stock, original condition.
The recommended mods for the silverface Bassman AB165 and Bassman 50 amps include:
AB165 to AA864 Conversion: This is the Bassman version of the ‘blackface mod’! The AB165 Bassman has it’s own wacky phase inverter, bias circuit and output section. CBS took over Fender in 1965, so this circuit from Jan 1965 (AB ‘1/65) may very well be a post Leo CBS design!
This mod converts the AB165 to ‘classic’ blackface specs. This is the same phase inverter, bias and output circuit found in the AA864 Bassman, AB763 Super Reverb, Twin Reverb, Deluxe Reverb, etc. It makes a HUGE improvement in tone and performance, giving a much richer sound that is much more musical, with much more clean sustain and a more ‘open’ feel.
Tweed Preamp in the Bass Channel: We convert the first (normal) ch to a tweed preamp! The tweed preamp mod in the normal channel is an excellent option and a great voicing. Thicker tone with more midrange emphasis and lends itself towards earlier breakup. It gives you another whole tone option at your fingertips, and still full-on classic Fender! Sounds great for both guitar AND bass!!
We like to send the player back a blackface amp that blows away the tone & performance of the amp that was sent in!
After an overhaul, your amp will be good to go for a very long time circuit wise.
Current turnaround time is approx 10 – 20 business days.
Please let me know if you have any questions at all!