Is this a legit vintage Ampeg B-15???

[bostero77]

hello to all tb'ers

i went to check out a vintage Ampeg B-15 in pretty rough conditions that i found in the local CL. it was abandoned in the garage for many years but it worked and sounded great so i brought her home at a lower price (i think...) than these amps are sold for.

At home, with the excitement and adrenaline in much lower levels, i started to clean it up and look for serial number to get more information about this portaflex.
I did some research and i read that the serial are at the back of the amp under the power cord and in the speaker cab interior as well and that both should match. Voilaaa... i didn't find any serial number neither on the amp or the cab...

at this point im concerned if i bought a knock off of a portaxlex.

can you please help me to find a serial or more info about this amp?

thanks in advance!

 

[beans-on-toast]

Congratulations. No knockoff. Just needs some TLC.

Your amp was discussed here: http://www.talkbass.com/threads/wow.1128141/

Do you have a pic of the inside of the cabinet showing the speaker?

 

[bostero77]

thanks beans!

LoL. i did not know other TB'ers had an eye on the same amp

the speaker doesn't seem the original. i can't find any name on it, just a few numbers (see pics)

 

[B-string]

Speaker is a Utah I don't believe came stock Invalid Link Removed

 

[bostero77]

Speaker is a Utah I don't believe came stock Invalid Link Removed

thanks so much B-string!

im not considering changing the speaker any time soon (it sounds pretty good to my ears right now) but are these Utah speakers recommended for B-15s?

thanks again!

 

[beans-on-toast]

If the speaker sounds good, that's all you need. It looks vintage and heavy duty. Never tried one in a B-15 cab. The image of the inside confirms that it is a later (60's) single baffle cab mated with an earlier head.

People feel that the closest modern equivalent to what was originally in your cab is an Eminence Delta 15A at about $100.

There's a lot of info in the TB portaflex wiki: http://wiki.talkbass.com/index.php?title=Category:Ampeg_Portaflex_wiki#Introduction

The literature section is a good place to start. Parts are available from fliptops.net.

 

[B-string]

Recommended? They could be used as a replacement, Utah had many models that sounded pretty good. They also produced some pretty unspectacular models. They could be found as stock units in Fender on occasion. I had a pair of similar 15s I beat pretty well with more wattage back in the day that I really enjoyed.

 

[beans-on-toast]

I like the look of the metal dust cap on the speaker.

 

[B-string]

I like the look of the metal dust cap on the speaker.

I couldn't afford Altecs so I bought a pair like those from Allied Radio. For the younger generations, those days you filled out an order sheet by hand and snail-mailed a check or money order. Delayed gratification.

 

[bostero77]

If the speaker sounds good, that's all you need. It looks vintage and heavy duty. Never tried one in a B-15 cab. The image of the inside confirms that it is a later (60's) single baffle cab mated with an earlier head.

People feel that the closest modern equivalent to what was originally in your cab is an Eminence Delta 15A at about $100.

There's a lot of info in the TB portaflex wiki: http://wiki.talkbass.com/index.php?title=Category:Ampeg_Portaflex_wiki#Introduction

The literature section is a good place to start. Parts are available from fliptops.net.

thanks very much. can't stop reading the wiki now!

 

[bostero77]

Recommended? They could be used as a replacement, Utah had many models that sounded pretty good. They also produced some pretty unspectacular models. They could be found as stock units in Fender on occasion. I had a pair of similar 15s I beat pretty well with more wattage back in the day that I really enjoyed.

wow. i guess i will stick with the current Utah till it goes bad.

 

[MR PC]

Great score! not only is it legit, but that head is the very best sounding of the 60's B15 crop, imho. Have fun, don't change anything right away if it ain't completely broken, take your time.

 

[bostero77]

so if this is a B-15NF is it a year 1966?
the head has no serial numbers on the chasis. im just curious how old is this beauty. thanka

 

[bostero77]

Great score! not only is it legit, but that head is the very best sounding of the 60's B15 crop, imho. Have fun, don't change anything right away if it ain't completely broken, take your time.

thanks! i have to say that when i first plugged it in with my fender jazz i just couldn't believe how warm, sweet and fat was the tone at low volume.
my main rig is a svt mti which i love but this little monster has something on its own!

 

[coreyfyfe]

The head is earlier, given the 5U4 rectifier it would be a late run B15N. They went to the solid state rectifiers with the B15NA and NB models and back to tube rectifiers with a 5AR4 in the B15NC. The NF was introduced in late 65 and the single baffle cabs in 66/67. So the head is a 1960-61ish model, the cab (including the tray/schematic) is from 1966-67. The exact timeline should be in the wiki, either through pictures or the schematics.

Having looked through the wiki schematics a bit, the June 1960 B15N schematics show a rotary standby switch and are the last set with a 5U4. The B15NA schematics aren't dated but have the solid state rectifiers. The next set is the B15NC from Jan 64 with the 5AR4. The B15NA image shown in the wiki has the more well known 3-switch layout and open chrome sides. I may have my timelines off and I'm sure someone will correct me if I do, but I don't think they went back to the 5U4 before going to the 5AR4 so this would have to be somewhere between the 1960 dated B15N and the introduction of the B15NA. If that is all correct, this amp could be one of the last design changes before the solid state rectifiers were introduced.

 

[beans-on-toast]

so if this is a B-15NF is it a year 1966?

Look at the date codes on the pots. 137YYMM where 137 is a CTS pot, YY is the year, MM is the month. If it were a 66 from the 12th month, you would see 1376612

A lot has been changed in your amp, the channel 1 pot is a replacement but the others look original.

 

[B-string]

I could almost read one date code, the focus was just off no much.

 

[bostero77]

Look at the date codes on the pots. 137YYMM where 137 is a CTS pot, YY is the year, MM is the month. If it were a 66 from the 12th month, you would see 1376612

A lot has been changed in your amp, the channel 1 pot is a replacement but the others look original.

yeah. the Volume 1 and the Volume 2 look different.

i took a few pics of the pots here:

 

[B-string]

WELL, in the last pic you have a 1962, 39th week!

134 62 39 (1376239)
CTS 1962 39th week.

I make out two 1962's and a 1960 pot.

 

[bostero77]

WELL, in the last pic you have a 1962, 39th week!

134 62 39 (1376239)
CTS 1962 39th week.

I make out two 1962's and a 1960 pot.

thanks Bstring!
that one is the Volume 2 pot that i think is was a replacement.

i just removed a little of wax on the eq pots and i read 1346039. i think is a 1960-1961 model.

this is fascinating!!!