Update on the Pro Jr. Project

I’ve received several emails with good suggestions for the tube and speaker swaps in the Fender Pro Jr harp amp project.:

-12AY7 in V1 (suggested several times)
-12AU7 in V1
-12AT7 in V2
-12DW7 in V2

(V1 is the preamp socket; V2 is the phase inverter)

-Jensen C10Q reissue speaker
-Weber 10 Sig alnico straight cone speaker
-Weber 10A150 speaker

I emailed Ted Weber and he suggested a 10F150-O, but that costs 90 bucks and I’m trying to keep this project down to a moderate level. I’m still looking around for an interesting used speaker. If nothing turns up I’m leaning toward the Weber Sig ceramic with straight cone. I use that speaker in my 2x10 cab and I know it sounds great with harp.

I ordered a NOS JAN Philips 5751 preamp tube from Tube Depot in Memphis. On a whim I visited my friend Al in his tube heaven junk store and found an old used Sylvania 12AY7 with some corrosion on the pins. I’ll try and clean it up and see how it sounds.

In the article about my Fender silverface Champ project I dug into the issue of the Negative Feedback Circuit in Fender amps and how it affects harp tone. The NFB circuit in the Pro Jr. is a violet wire that extends from the middle of the circuit board to the speaker jack. I’ll unsolder or clip the wire and tape it off. Some players install a switch or pot in the circuit to adjust the NFB, but with the Champ project I discovered that zero NFB is best for my tastes.

I had heard that the green filament heater wires in the Pro Jr are not twisted and are routed along other wires that could easily pick of noise from them. In my Pro Jr. they aren't twisted, but they are dressed pretty well, crossing other wires at a 90 degree angle. The amps does not seem noisy so I'll leave well enough alone.

The Pro Jr. has a bleed circuit that drains the amp of any power within a few seconds of shutdown, which is supposed to keep you from getting shocked. Still, I short the no. 1 pin of the V1 tube socket to ground for extra caution before working on the guts of any tube amp. I suggest you do the same.

Jump to Fender Pro Junior Harp Amp Project – Speakers

Review: Danelectro Fab Echo pedal

First of all, this pedal sells for $14.99, about a tenth what you would expect to pay for a decent delay pedal. That, and a smattering of positive reviews from guitar players got my attention.

The Fab Echo is not long on features, of course. But it does one thing rather well… it has a nice warm slap-back that works well for harp.

Harp players argue constantly about which delay pedal is best: Analog or digital? Maxxon, Ibanez, Boss, or Digitech? If you are a Chicago-style blues player – if you lust after Little Walter’s tone – all those delay pedals have way more features than you will ever need. What sounds good for traditional amped blues harp is a touch of greasy slap-back echo. That’s all.

And that’s where the Danelectro Fab Echo comes in. It has two controls, Repeat and Mix. The repeat knob controls the number of echos, with a single echo at the minimum position. That is what we want for harp. The other knob controls the output mix of dry and wet signals, from all clean to all echo. Essentially, this is s a one-knob pedal for harp players.

What you pay all the extra money for in other delay pedals is the Delay Time control, which is conspicuously missing from the Dano Fab Echo. But if you only use one echo – a “slap-back” – then the lack of a Delay Time control is pretty much meaningless.

I recorded three very brief sound clips to give you a basic idea of how the Dano Fab Echo pedal sounds for blues harp. The first clip has the Repeats control at the minimum (one slap) and the Mix control at the max (all echo, no clean). This clearly illustrates the delay time built into the pedal, but you sure would not want to use it this way.

Clip 1

The next clip has a similar riff, with the only change being the Mix control is at 50 percent. The pedal sounds best to me at this setting

Clip 2

For reference, here is a very short clip with the pedal switched off.

Clip 3

How do you think the Dano pedal sounds? For its price and simplicity I think it sounds good, but lately I have preferred playing dry… no reverb or delay at all. But, Crikey! For chump change you can have a usable no-frills slap-back pedal in your bag of tricks. At the very least it makes a great back-up if your fancy delay pedal (most of whose features you never use) ever craps out.

Observations:

This pedal is made of plastic, but it is hefty and feels solid. The jacks are soldered onto the circuit board but don’t feel loose or cheesy. Product support at Danelectro is known to be pretty much non-existent, but if it breaks, what the heck. Just buy another one.

This pedal is not noticeably noisy. The pilot LED is a brilliant blue. The controls are a little confusing at first because they face away from you as you look at the pedal. It has a 9V power connector so you can use a common power adaptor instead of hassling with batteries.

I ordered it on a Monday evening from Musicians Friend online, and it arrived at my house in Denver via USPS express mail on Thursday morning.

Test Notes:

I used a OneSpot adaptor to power the Dano pedal. The amp was a vintage Masco ME-18 and 2x10 cab. The recorder was a Zoom H4. Instead of mic’ing the amp, I used the H&K Red Box Pro DI to avoid room effects. The harp mic was a Peavey H5 Cherry bomb with Shure CM element. The harp was a Hohner Marine Band Deluxe in the key of B-flat.