1. Welcome to TalkBass, the Premier Bass Player Community and Information Source. We've been uniting the Low End Since 1998!

    We're glad you've found us. Register a 100% Free Account to post and unlock tons of features.

Vintage Ampeg SVT head and cab

Discussion in 'Amps [BG]' started by sean b 1970, Dec 31, 2013.


  1. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
    Looking at purchasing a vintage SVT for steady live use. Would love to hear opinions on Blueline vs. Blackline, Linden, NJ vs. Magnavox as it pertains to tone and reliability.
    For eg. There is a 1970 Blackline made in Linden, NJ listed for sale recently. Is there a difference (tonally and reliability wise) from this amp over say an early Magnavox model with similar cosmetics ( ie. Black Rocker switches, squared corners on blacklines) or even a later 70's model when they switched to white Rocker switches and rounded corners.
    Also, opinions on Cabs. Vintage vs. Heritage or even the other new line of cabs from Ampeg. Slant back vs. Refrigerator 8x10. Single 8 x 10 vs. Two 4 x 10's.
    And lastly, and I only ask this because there seems to be such a sliding scale; what is a fair price for all of the above and what should I look out for if something is priced low? (replaced transformers, good parts/ bad parts )
    I'm not super tech savvy but can" call a friend" if I need to so don't be shy about specifics...
    Thanks in advance for your help!
     
  2. beans-on-toast

    beans-on-toast Supporting Member

    Joined:
    Aug 7, 2008
    The early amps all sound the same. The transformers come from the same company. I find that the blue line is more desirable but solely on looks.

    A 1970 would be a blue line so the one for sale that you are looking at is a later model.

    In terms of reliability, they are the same. All built like tanks. How reliable your amp will be is based on the condition of the amp. An amp that looks good and has been well taken care of is going to take less work to clean it up and bring it up to spec.

    Count on having to take the amp to a tech and putting more money into it to bring it up to spec. How much you have to put into it will depend on the shape that it is in. An amp that is in good shape is worth paying more for and may cost less in the long run in terms of tech costs. At the same time, beaters can be great sounding amps. Everything on them can be fixed.To what extent depends on what you want to put into it post purchase.

    New tubes are a possibility and can be expensive. Ask if any mods have been performed. Ask what maintenance was done. Ask if has been recapped. Look to see if it has a two or three conductor power cord. Look at what tubes are in the amp and if they are original or if they have been replaced with currently manufactured products.

    Try the amp, and test that all the switches do something. Same with the tone controls. See if the pots are scratchy when you move them. How does it sound?

    Look in the back of the amp for signs of rust on the chassis and transformers. Some rust on the transformers is fine, too much is not good. Look for signs of modifications like extra holes drilled in the chassis. See if all the parts are there. Back silk screened plate, the silver mesh cover over the back.

    There info and pics of some early SVT's here.

    As for cabs. If they cab is in good shape with no issues, it will sound great. There are lots of good used ones out there. The top of the line choice is the current Heritage 810. You can't do better. Flat back cabs are next but have a lower wattage capacity. Your can't push them as hard. With an older cab you might have to get into speaker recones. Again, added expenses. Getting eight speakers reconed plus the initial cost of the cab can be as expensive as a new cab.
     
  3. StuartV

    StuartV Out of GAS!! Supporting Member

    Joined:
    Jul 27, 2006
    Location:
    Bristow, VA
    If you don't care about vintage snobbery, you should also consider an SVT VR. They can usually be found for a bit less than a vintage SVT. And they look basically the same. And have a few nice-to-have modern appointments. And are easier to re-tube when necessary (rarely).

    I have an early 70s SVT and had a MIA SVT VR. I compared them back to back and ended up liking the vintage one better. But, I could only hear the difference when I recorded them back to back and then listened to the recording with good headphones. And even then, I would chalk the difference up to the VR having all original (i.e. modern production) tubes where I had completely re-tubed the vintage SVT using good NOS tubes for all the preamp and driver tubes and top-of-the-line new production tubes for the power tubes.

    In other words, I think if I re-tubed the VR the same way, I would expect it to sound just as good - even in a super fine comparison like I did.

    I don't have much personal experience with a lot of different cabs. But, the most popular opinions here on TB seem to be that the Heritage 810 is the best Ampeg cab you can buy, if you want that old school rock tone. I have one and love it. But, if that sound floats your boat, another cab to consider is the Bergantino NV610. It's constructed using sealed pairs of 10s, like the Ampeg 810, so it sounds VERY similar. And it's a lot more compact, lighter, and still has big power handling. I have one of those, too, and hope to be posting some clips soon, comparing the sound of the Heritage 810 and the NV610.

    In other words, I have what is my personal Ultimate Rig in my vintage SVT plus Heritage 810. But, I honestly can't say that a nicely-tubed SVT VR plus a Berg 610 wouldn't sound just as good, and have the benefits of being not old and somewhat fragile (as MY vintage SVT has proven to be, anyway).

    In the end, if it was me shopping, it would probably come down to what I could find locally for a decent price. Any old SVT in good shape, or SVT VR, and most any Ampeg 810 or Berg NV610 that I could find, and I'd be set.
     
  4. JimmyM

    JimmyM Supporting Member

    Joined:
    Apr 11, 2005
    Location:
    Apopka, FL
    Disclosures:
    Endorsing: Ampeg Amps, EMG Pickups
    To me, an SVT is an SVT is an SVT. I have used them all and I have been deliriously happy with any of them no matter when they were made, as long as they worked.
     
  5. Register to disable this ad
  6. Kmonk

    Kmonk

    Joined:
    Oct 18, 2012
    Location:
    South Shore, Massachusetts
    Disclosures:
    Endorsing Artist: Fender, Spector, Ampeg, Curt Mangan Strings
    I have owned several SVT heads manufactured from the early to late 1970s. All were great.
     
  7. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
    Thx for the link to the Blueline club page, still reading...lol Do the 6146's make a huge difference and if so what specifically and how much extra is a Blueline with no mods going to cost over a 70's Blackline in similar condition?
     
  8. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
    Previous post meant for you b-o-t
     
  9. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
    Thx to everyone for the input btw, going to check out this berg cabs too!
     
  10. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
    Sorry, just figured out the tag on feature here...do you also feel that way about the Blueline -vr?
     
  11. beans-on-toast

    beans-on-toast Supporting Member

    Joined:
    Aug 7, 2008
    The 6146 based amps were blue lines and were only available till some time in 1970. Many of them were converted to 6550's. Most 6146 amps are in pretty rough shape with a lot of rust on the chassis. They had an unpainted chassis. It isn't unusual these days to see blue lines in very good condition selling for $2K and up. In general blue lines sell for a little more than black lines. Better deals can be found. But usually it comes down to finding a good deal. Nice SVTs can be found at much more reasonable prices though.

    By the way, I don't consider a recap or a three conductor power cord or replaced cathode or plate resistors or even a new fan as a mod. These are basic things done as standard maintenance to keep the amp operational. They don't lower the value of the amp. Mods are holes drilled in the chassis or faceplate to add features like a DI or switches for one thing or another.
     
  12. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
    Sonically is there a huge difference with the 6146's?
    Got a line on a early Magnavox where the input transformer is a replacement, should I be concerned or look for anything with it that makes it a good repair or bad?
     
  13. beans-on-toast

    beans-on-toast Supporting Member

    Joined:
    Aug 7, 2008
    People who have both of them claim that amps with 6146 and 6550 sound the same. There are slight differences in the power supply voltages but that is to accommodate the tubes, not for a sonic reason.

    Some companies such as Mercury Magnetics (check out their SVT transformer prices on their web site) or Heyboer make SVT replacement power filament and output transformers that are drop in replacements. I would want to know if the replacement transformer is one intended for an SVT or something a tech decided was good enough. There is a big difference between the two. If it is the filament, it isn't as big a deal as long as they used a part that meets the spec. An output transformer affects the sound of the amp. A power transformer can as well beds on the voltages and how it functions in the amp. You need to find out the details of what was installed. If it isn't an SVT transformer, it could affect the sound. This might be why they are selling the amp at a lower than normal price.

    BTW, you said input transformer. Which one did you mean, power, output, or filament ?
     
  14. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
     
  15. beans-on-toast

    beans-on-toast Supporting Member

    Joined:
    Aug 7, 2008
    We'll figure it out. Perhaps this will help. Below is an image of a 1975 black line SVT power amp. I labeled the transformers and filament. Based on this image, can you identify which one was changed? As a point of reference, the tubes are at the back of the amp.


    [​IMG]

     
  16. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
    Based on your pic, my photo is taken from the back of the amp and the transformer in question is located on the left. I am assuming that you would not be able to see the choke from the back so my gut tells me it is the power transformer.
     
  17. sean b 1970

    sean b 1970 Supporting Member

    Joined:
    Dec 25, 2013
    Location:
    Boston,MA
    I've managed to save the pic to my phone, how do I post it?
     
  18. JimmyM

    JimmyM Supporting Member

    Joined:
    Apr 11, 2005
    Location:
    Apopka, FL
    Disclosures:
    Endorsing: Ampeg Amps, EMG Pickups
    I feel that way about all of them, the VR's, CL's, the 2 Pros, the MTI SVT's, the old Blue Lines...there might be ever so slight differences in them but they all sound like SVT's to me.
     
  19. JimmyM

    JimmyM Supporting Member

    Joined:
    Apr 11, 2005
    Location:
    Apopka, FL
    Disclosures:
    Endorsing: Ampeg Amps, EMG Pickups
    I feel that way for sure. My 69 with 6146b's sounds like my Heritage SVT-CL. Pretty much identical.
     
  20. beans-on-toast

    beans-on-toast Supporting Member

    Joined:
    Aug 7, 2008
    Based on your description of the replaced transformer, it doesn't sound like it is an SVT transformer. Here is a drop in replacement one from fliptops. It costs $255 plus shipping and installation. Costs can add up. Unless you can identify what is in there now, you will not be able to determine if it is the right one for the amp. A tech would need to measure the voltages. But there is more than just the voltages when looking at the performance of a transformer. Nothing saying that need to put in an SVT transformer.

    If you like the sound of the amp as it is and the price is right that's all that counts.
     
  21. Jim C

    Jim C

    Joined:
    Nov 29, 2008
    Beans,
    Always appreciate the education on amps from you.
    Maybe there could be a sticky of tech notes by amp brand as you've done above.

    Needless to say, thanks to all the other techs that explain the design, history, and maintenance of MI amps on this board; I won't list for fear of omission but you know who you are.
     

Share This Page