NAD - Fender Prosonic

Discussion in 'Amp Central Station' started by horseman308, Jun 17, 2017.

  1. horseman308

    horseman308 Tele-Holic

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    Brought it home this afternoon. Got it for $550 out the door. It's in better condition than I initially thought. CR serial number with a green jewel light. One Celestion speaker and one WGS G10C. Tilt back legs. It looks like a previous owner had an impedance switch wired in where the extra speaker jack is. Useful for trying out different speakers in the cab (I'm interested to hear how my 12" V30 sounds), but makes it harder to use an extension cab. The Prosonic pop is there when changing channels, but it really isn't that loud. It really won't be noticeable at gig volumes I suspect.

    This thing sounds fantastic! I see why people can get hung up on how gainy it can get if you really crank the Gain 2 knob, but with it off and Gain 1 on about 2-4 it was just right for me. Cleans are everything I hoped for. I tried a couple other amps in my price range - a Classic 50 in 410 but it wasn't any contest. I hoped to try out a Carvin Belair ($350, so it was appealing), but it didn't work so I never heard it.

    Also, the first thing my 4-year-old did when I got it home was turn the dials and day, "I'm turning these all to 10!" I win at parenting.

    2 questions (for now):

    1) Anybody know what model footswitch works with the Prosonic? They didn't have the original. Both a 2-button switch and 1-button switch from their stockpile of extra switches had the problem of rendering the reverb inoperable whenever the switch was plugged in.

    2) How can I verify what the actual impedance of the speaker impedance output is? I just want to verify that the 3 positions on the added switch work as they are labelled (see picture).

    Thanks![​IMG][​IMG][​IMG][​IMG]
     
    Last edited: Jun 17, 2017
  2. jackinjax

    jackinjax Friend of Leo's

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  3. horseman308

    horseman308 Tele-Holic

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  4. TimothyC

    TimothyC Tele-Afflicted

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    Nice amp! Congrats!
     
  5. tonejam

    tonejam Tele-Meister

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    welcome to the Prosonic club. Hope you enjoy yours as much as I do mine.
    As I said in an earlier post there is a ton of useful info on this site re these amps. Here's a pic of mine.
    Here's a pic of mine. ProSonic1 - Copy.JPG
     
  6. codamedia

    codamedia Friend of Leo's

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    Fenders best amp since the Silverface era... IMO of course.
    Great price, great condition. Congrats.

    I am sure these use the '65 re-issue foot switches... just with a different label. The re-issues select "VIB & REVERB" while on the Prosonic they will likely switch "DRIVE & REVERB". The label is just a label - it means nothing. They are basic on/off switches connected to a stereo jack. One switch shorts out the TIP the other switch shorts out the SLEEVE.
     
    Last edited: Jun 18, 2017
    Electric Mud and xafinity like this.
  7. brookdalebill

    brookdalebill Tele Axpert Ad Free Member

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    Congratulations, great sounding amps!
     
  8. twangjeff

    twangjeff Tele-Afflicted

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    Man what a killer deal!
     
  9. gridlock

    gridlock Friend of Leo's

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    Congrats. I need to test drive a Prosonic.
     
  10. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    This may help -

    "Gain 2" isn't a "gain" knob - it's a pot that affects only the gain "sound". It's a midrange control. That's all. Only "Gain 1" affects the actual gain level.

    And I say "sound" because it's a one-channel amp. The clean section of the preamp is never out of the single path, and the gain section is always connected at the from end, although it has no direct affect on the signal. The foot switch changes a relay that opens the back part of the gain section's signal path.

    Each preamp tube has half in one amp section, so your tone voicing stays very consistent with only the gain kicked up unless you revoice the gain section of the amp.

    There are quite a few mods that can be done if you want to change the gain level and add some clarity to the highs. With the high-quality build and hand-wiring they are excellent platforms for players that do their own tech work.

    FWIW they are not easy amps to "test drive". It takes some time to dial-in personal voicing - everyone seems to set thew controls a little differently. They are also *very* touch sensitive, and it's not ideal amps for those that leave their guitar volume or tone controls (or both) on full most of the time. The amp works far better if you back them off and use very small adjustments while playing, along with very light attack.
     
  11. horseman308

    horseman308 Tele-Holic

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    Thanks for those thoughts. I knew the Gain 2 wasn't really more gain and that it's really a single channel with the extra gain stages. That's one of the reasons I like it so much. I always preferred my OD to have the same tone as my clean but dirty, so this is perfect.

    I am guilty of being the "everything on 10" guitar player, but I've been working hard to learn better in the last few years. I think this will really help. I had a chance to crank it (all the way) this afternoon while I was home alone. My goodness what a sound. I definitely prefer the class A rectifier setting, but I can see the advantage of the others. The channel pop wasn't really noticeable at volume, and strangely enough the reverb hum was absent (it came on strong after 10 minutes last night but not at all today; weird).

    I've found the Fender tech notes for addressing the pop and reverb hum, so I'll get those done when I have it checked out soon. Some new tubes from Eurotubes will complete the package and I think I'll be set for a while as i learn my way around it. And maybe I'll put in my 12" V30 in place of the 2 10's to see what that sounds like.
     
    Last edited: Jun 18, 2017
  12. Wally

    Wally Telefied Ad Free Member

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    Congrats...great deal. That amp needs a thorough evaluation so that you know exactly what has been done...and so you can trust the labeling on that impedance switch. Re: that footswitch.....their eis a power circuit for the LED's in the pedal. I would advise you to get a correct footswitch....that seems to be a drawback that accounts in part for the great price.
     
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  13. paratus

    paratus Friend of Leo's Gold Supporter

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    Congrats on your new amp, what a score!
     
  14. horseman308

    horseman308 Tele-Holic

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    Thanks Wally. I ordered a correct switch so I think that will do the job. I got $50 plus sales tax off the sticker price of the amp, which is just about what the footswitch cost, so call it $600 plus tax for the amp. I'm happy.

    I had the chassis out a little while ago to eyeball the filter caps and impedence switch in particular. I'll add pics and would love your thoughts. I was able to follow the wires for the different impedences from the transformer to the points on the rotary switch, and they match the label.

    On the filter caps, one of the 47uf 500v caps has a little bit of brown substance (the electrolytic?) just leaking out around the lead. The others all appear fine on the outside, but I assume this really means it's time for a cap replacement. It should show in the pics. Thanks for any feedback.

    I've got more pics of the guts inside the chassis and of the caps, but I didn't want to overdo it unless needed. Just let me know. 20170619_121816.jpg 20170619_122939.jpg 20170619_122932.jpg 20170619_121423.jpg
     
  15. Wally

    Wally Telefied Ad Free Member

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    I don't like the looks of that cap, either, although that is not a normal outlet for physical leakage. The outlet would be that hole you see there. I would replace the filter caps and the biasing caps.
    As for the OT taps, I would take resistance measurements at the end of a speaker cable plugged into the Jack...with the amp off. The resistances will not be large...1-4 ohms probably. The lowest resistance will be the 4 ohm tap and the largest will be the 16 ohm tap. It is likely that the switch was installed correctly, but I personally would have to know for sure.
     
  16. horseman308

    horseman308 Tele-Holic

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    Thanks again Wally. I'll be getting the caps done forthwith.

    I took readings the way you described. I set the multimeter for the lowest ohm setting and measured off the tabs for positive and negative of the speaker cable. I got readings of 0.4 - 0.5 ohms for the 4 ohm setting, 0.7 - 0.8 ohms for the 8 ohm setting, and 0.8 - 0.9 for the 16 ohm settings. Does that sound right? It sort of fits your described pattern but not quite. Thanks again.
     
    Last edited: Jun 20, 2017
  17. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    Ditto on the caps - that one looks like the lead was overheated, although oddly all the filter cap connections are very badly soldered - it should flow out, not look like it's wadded up in a ball!

    Honestly, I'd be hesitant to turn it on at all until it's been looked at by a competent tech - otherwise you could end up with an expensive repair. And as Wally notes there's no way to be sure what the impedance switch does until it's tested.

    Also, if you decide to use the effects loop change V3 to the stock 12AX7. I can't figure out why anyone would change it to a lower-gain tube - it serves as both the send and return, and lowering the gain would lower the effects signal level - not usually a good thing unless something in the circuit was changed.
     
  18. Wally

    Wally Telefied Ad Free Member

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    Horseman, yes, those numbers support the labeling on the switch.
     
  19. JDB2

    JDB2 Tele-Meister

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    Those caps don't look like the original Illinois caps - They have been replaced once already
     
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  20. horseman308

    horseman308 Tele-Holic

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    That would be consistent with the other observations about the big blobs of solder and over heated lead. I probably will get them replaced anyway so I know for sure where I'm starting from, though.
     
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