Official Ampeg Portaflex Club

Discussion in 'Amps and Cabs [BG]' started by JimmyM, May 25, 2008.


  1. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    With two cabinets, both should be rated at 8 ohms. When connecting an extension 8 ohm cabinet, use the ext speaker jack, NOT the ext amp jack. Ext amp has a voltage divider on it the knocks down the level to around 20%.

    If you haven’t added a second parallel jack to replace the 4-pin connector, connect the main cabinet to the EXT SPEAKER jack, leave the 4-pin disconnected. Use the daisy chain on the back of your main speaker cabinet to connect the second cabinet.
     
    flatwound62p likes this.
  2. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Hey, Jim added a shopping cart to the website finally, eh? Dude really knows his tubes, and he's really easy to order from over the phone, but his website was always pretty basic when it came to ordering. I still just call him. Been down there a handful of times when I was in a crunch, too. But I'm done with NOS tubes unless I need a 6sl7.
     
  3. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Good to have a local place that you can count on.

    Nice guy to deal with. He’s very fast at getting orders out the door, no crazy shipping fees like some places.
     
    TinIndian and JimmyM like this.
  4. TinIndian

    TinIndian Supporting Member

    Jan 25, 2011
    Micco Florida
    I didn't even realize he was in Orlando until I was checking out. Great to have a resource like him relatively local.
     
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  5. flatwound62p

    flatwound62p

    Apr 24, 2017
    Australia
    Woah, thanks for the detailed info. I wish I'd had that to give to my tech a few months ago. Would have saved him quite a few grey hairs and saved me a long wait :thumbsup: The power supply section was apparently a train wreck, it got a full re-cap and a few out of spec resistors were replaced. It tested a bit over 100w clean at 4 ohms after repair and seems healthy now.

    The head has a 1/4" jack for the main output, I assume modified whenever it was seperated from the cab. I checked with tech and that one is as per the schematic, the extension speaker jack also has the resistor on it but he couldn't remember the value. So I think I see what you guys are saying about why the extension speaker output gives less power than the main out. Also makes sense why the catalog listed different wattages for BT1C 2x15 column cab and BT15D pair of 1x15 cabs rigs.
    Screenshot_20210515-203956_Samsung Notes.jpg

    I'll stick with using the main speaker output into the first cab and use the parallel off that cab into the second cab. Both are 8 ohm cabs.

    It's a really nice sounding amp. The heat is a bit of an inconvenience though ... Where do I put my beer? Thanks for the help guys :)
     
    gtmalone and beans-on-toast like this.
  6. KlankTank

    KlankTank Supporting Member

    Jan 26, 2021
    New Jersey
    @beans-on-toast,
    I just got this 62 B15 (and a Jet 12), Can you help me identify the missing component (3 spaces left of blue cap?) The crimped leads look like the ones on the blue cap but I cant find it's value on the schematic coming off the fuse holder. I'm using Mark's schematic that matches the one on my tray, but it looks like this may be something that was added before the next revision; B12NA & B15NA. That drawing says component "T" is C-100 ohm, H .49 ohm. I don't recognize the square wave looking symbol on the drawing either. Confused again!
    B15.jpg
     
    chupacerveza and beans-on-toast like this.
  7. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Nice amp, it looks all original. Expect the brown paper covered power supply caps to be bad. Keep the green ones, they are gold.

    The component that you’re asking about at is an inrush current limiter, it’s a protection device. Cold it reads 100 ohms, hot it reads 0.49 ohms, this resistance ramp down happens pretty quickly when the amp is powered up cold.

    I’ve rarely seen them in these amps. They run hot, they are removed when they blow. If you wish to install one, the NTC CL-60 thermistor is found in many amps today. See the Amphenol data sheet at this link. When installing, allow some air around it.

    https://www.mouser.com/ProductDetail/Amphenol-Advanced-Sensors/CL-60?qs=w3gjcs3NwciEQjXGFRAAAA==
     
    chupacerveza and KlankTank like this.
  8. KlankTank

    KlankTank Supporting Member

    Jan 26, 2021
    New Jersey
    Thanks Beans!!!
    "The component that you’re asking about at is an inrush current limiter, it’s a protection device. Cold it reads 100 ohms, hot it reads 0.49 ohms, this resistance ramp down happens pretty quickly when the amp is powered up cold."

    Meaning that happens if the standby was switched on too soon, or the inrush occurs after the standby goes on regardless?

    "I’ve rarely seen them in these amps. They run hot, they are removed when they blow. If you wish to install one, the NTC CL-60 thermistor is found in many amps today. See the Amphenol data sheet at this link. When installing, allow some air around it."

    Would it be correct to assume that is why (the seller said) it would not power up? Everything else looks intact but I did not want to apply power before identifying/replacing it. Is there a more efficient workaround or mod?

    Beans and [email protected], your help is appreciated more than I can express in words. The B15NF you helped me with prior to this has been gigging for the last three weeks without a hitch. Had a bad tube causing the intermittent popping and Mark, your cabinet kicks some serious bASS!!!
    I was a bit concerned with the heat/smell the first week, but I'm pretty sure now that it was just the dust burning off. I Pushed it hard this week and that thing cranks to almost 2 o'clock on the volume before a hint of breakup.
    Joe
     
    Vintage-Blue and beans-on-toast like this.
  9. ChoGall

    ChoGall

    Jul 16, 2020
    Does the PF-350/500 sit flush on top of a AV-210? I'm thinking of picking up one to sit on top of my AV-210 stack, but wanted to check if it would be sitting comfortably up there, or if would be teetering the whole time.
     
    beans-on-toast and chupacerveza like this.
  10. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    The location of the limiter being on the primary of the power transformer is not much value if you use standby because the heater is drawing current. The 5AR4 is on the high voltage circuit and it also ramps up. Not all rectifier tubes do this. You amp would have come with a 5U4GB rectifier tube. People use a 5AR4 in it’s place, it provides less sag and distortion when the amp is pushed.

    If the thermistor is blown open, yes this could prevent the amp from powering up. Either remove it and replace it with a wire or simply clip a wire in place across the thermistor to test if this is the problem. It could also be the fuse or a blown power transformer primary.
     
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  11. chupacerveza

    chupacerveza Supporting Member

    Jan 3, 2011
    Austin, TX
    I don’t recall whether it’s an exact fit… but I do recall that it’s quite steady.
     
    beans-on-toast likes this.
  12. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    The 350 is fine on the 210av. The 500 and 800 are a little wider than the cab, but the feet will fit on the amp corners if you place it right.
     
  13. line6bassist

    line6bassist Supporting Member

    May 16, 2009
    san antonio/austin
    Hi Everyone, I'm thinking of getting theAmpeg PF-410HLF or the Ampeg Pf-115HE. They seem to have a vintage and modern vibe which I love. The videos I've seen has been with matching heads. Will any of these cabinets work well with a Genzler 800 or Gallien Krueger legacy 800? Thanks everyone
     
    beans-on-toast likes this.
  14. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    The cabinets will work with any amp, no problem. That 410 is one heavy cabinet. An 810 isn’t that far off.
     
  15. ChillyDog

    ChillyDog

    Nov 29, 2011
    Glens Falls, NY
    Is there a particular revision to look out for when buying a cab for flip topped use with one of the tube models?
     
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  16. KlankTank

    KlankTank Supporting Member

    Jan 26, 2021
    New Jersey
    Bypassing the limiter had no positive effect. There is something else going on. It looks like the PT may have been changed out (it had solid core wire) and one of the leads was purposefully disconnected from its place on pin 8. As I say at work "further troubleshooting required". Going to shelf it and get to the B18 power cord conversion. Do you have a schematic for that task? The Wiki has a great one for the B12 but i could not find one for the B18 with ground and standby.
     
    beans-on-toast likes this.
  17. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    The procedure for the B-18 is the same as the B-15, it is above the SB-12 details:

    Technical - Amplifier | TalkBass.com

    If you want to retain the ground switch with the death cap, see below the SB-12 section. You can use a original two position switch and eliminate the middle position. With the three conductor power cord, many remove the death cap. If the death cap in your amp is shorted, it will affect the power transformer.

    Ask of anything is not clear or you just want to be sure about anything. You have to be comfortable doing this.

    To test the transformer, eliminate the thermistor by removing it and shorting the connection. Remove ALL the tubes. Apply 120VAC and measure the AC voltages on the primary and secondary sides. Check the standby circuit, if there is an issue there there will be no high voltage. Look for the service manual on the Vintage Blue web site.

    If pin-8 of the rectifier is disconnected, the amp is not going to work.
     
    Last edited: May 26, 2021
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  18. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    There’s a different reinforcing structure that is lower. As far as I know there isn’t a revision number to look for. I don’t have in image. Best you can do is find a recent model with an inside the cabinet shot. Hopefully, someone here can help.

    I’d call Ampeg customer service just to be sure. Ask about the PF210 and PF115 and how the tube amps fit.

    Sweetwater has an internal shot, you can see the brace/shelf of a newer model at the back of the cabinet.

    0C972BED-6299-4475-933D-96261B1E8D70.jpeg
     
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  19. gtmalone

    gtmalone

    Sep 30, 2015
    Allen, TX
    Earlier 2x10 cabs look like this with a brace running front to back. Does anyone have a recent 2x10 they could take a picture of? Do the earlier 1x15 cabs have a similar brace?

    i-hHR9fX2-L.jpg
     
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  20. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    The last two posts show the pics.
     
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  21. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
    Jun 19, 2021

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