difference between two ampeg SVT

[tdkappa]

Hello,
first of all sorry for my english, I'm italian anf I don't speak and write english very well.

Can You explain me the main difference between this two Ampeg SVT heads ?

In my google drive ( https://drive.google.com/drive/folders/1..._lax49gpke ) or in the attachments You can find the photos of the two amp:

1st model:
svt1-1.jpg
svt1-2.jpg
svt1-3.jpg

2nd model:
svt2-1.jpg
svt2-2.jpg
svt2-3.jpg

The 2nd model have the same range of frequnnce in the midrange (200, 800 and 3k Hz) and doesn't have the reverb knob, like the guitar model.

What are the main difference? are both for bass?
Or wich one can be better o what are the difference in the sound?

Thank You a lot for any answer !

[AEB-1]

There were several generations of SVT heads.  The first generation (about 800 units) had 6146B output tubes. From the front they had plastic paddle switches which were really cool but broke off easily. The output section could catch fire if you pushed it hard. Your #1 head is a second-generation model that used 6550 output tubes to increase reliability of the output section. The switches were changed to conventional toggle switches. These were manufactured when Ampeg was owned by Magnavox. These heads are most common and have most of the original design except the output tubes.  Ampeg was later sold to Selmer. Your #2 head is a Selmer era head. Things went downhill as Selmer redesigned the SVT and V series to make them cheaper to produce and "modernized" the graphics to give more detail about preamp controls that had been there all along. Some people say it looks like a 1958 Buick!  Internally the amp was redesigned, including the power supply layout.  Your #1 SVT is the "read deal" and #2 is still an SVT but not nearly as coveted.  SVTs never had reverb. They were "real" rock and roll amps made to "Part your hair at 50 feet", as Ampeg advertising stated. With 8-10 cabinets, they work great for bass or guitar. The SVT and V series preamps are amazing, but few musicians learned how to harness the capabilities.