SVTII vs SVTIII

[molan]

I've recently picked up an SVTII as part of a multi trade. I'd never considered an Ampeg before because I always thought of them as 'rock monster' heads only to be used with an 8x10 stack!

Having played through this head a few times I'm really surprised at what a lovely pure tone it has, have tried it through a few cabs and seems to sound really nice through all of them.

Problem with it of course is that weighs more than the average child & is a beast to lug around. Ampeg quote about 70lbs for it but with a flight case as well it's even heavier.

I noticed that the III has pretty much the same front end as the II but has a solid state power circuit (and only weighs 26lbs!) & wondered how close it gets tot he sound of the II?

Is it those wonderful 6 glowing power amp tubes that are making all the difference or have Ampeg managed to replicate the core oft he sound without the weight, and hassle, of the power amp tube section?

Edited August 17, 2008 by molan

[MythSte]

[quote name='molan' post='263990' date='Aug 17 2008, 03:52 PM']Is it those wonderful 6 glowing power amp tubes that are making all the difference[/quote]

Id say,
Yes.

[molan]

[quote name='ste_m3' post='263998' date='Aug 17 2008, 04:10 PM']Id say,
Yes.[/quote]

I had a feeling that might be the case

[chris_b]

I can’t comment on the SVT 2 but I've used an Ampeg SVT 3 PRO for about 8 trouble free years and I think they are great. They have 6 tubes in the preamp which gives out a huge, full, tone which can easily range from Dub to Mark King Slap. They are not transparent but have a vintageness that works really well with any bass I've used and my Boogie, Epifani and Bergantino cabs.

The only trick I have found which really improves the sound is to turn the master volume up as far as it will go without it hissing, about 3 o'clock, I have the gain at about 12 o'clock and control the volume from the bass. The clip light never comes on. You should also expect the fan to get noisy after a few years. Apparently they all do it but you don't hear it when playing.

In my opinion an SVT 3 PRO still beats any amp in its price range.

[jensenmann]

Having played Ampeg since ages I have to add one thing: the different becomes obvious with volume. The III has a MOSFET amp which will get to the point when it will not get any louder. Increasing volume with your fingers on the strings will not lead to increased volume in the amp. Same thing happens with the tube poweramp of the II BUT poweramp distortion rises and compression start to set in. These increased harmonics will give you the feeling that still it gets louder when you play louder (with your fingers not volumeknob), hence you have better control over the dynamic of your playing. The beauty of the SVT and SVTII and classic is to play with this poweramp compression and distortion this makes your sound come alive. (sorry, that´s LOUD) But you don´t want this for slapstyle. There it sounds annoying.
An alternative is the V4B (only 100W) or using KT88 tubes in the SVT (they compress a little earlier than 6550s) or leaving a pair of poweramptubes out.

[molan]

[quote name='jensenmann' post='269012' date='Aug 24 2008, 06:49 PM']Having played Ampeg since ages I have to add one thing: the different becomes obvious with volume. The III has a MOSFET amp which will get to the point when it will not get any louder. Increasing volume with your fingers on the strings will not lead to increased volume in the amp. Same thing happens with the tube poweramp of the II BUT poweramp distortion rises and compression start to set in. These increased harmonics will give you the feeling that still it gets louder when you play louder (with your fingers not volumeknob), hence you have better control over the dynamic of your playing. The beauty of the SVT and SVTII and classic is to play with this poweramp compression and distortion this makes your sound come alive. (sorry, that´s LOUD) But you don´t want this for slapstyle. There it sounds annoying.
An alternative is the V4B (only 100W) or using KT88 tubes in the SVT (they compress a little earlier than 6550s) or leaving a pair of poweramptubes out.[/quote]

That's interesting about leaving the power amp tubes out - what does this do to the power output in terms of wattage?

As you're obviously a bit of an expert on Ampegs I wondered what you thought about running the SVTII into an 8ohm cab. I've read that it really prefers to run into 4 or 2ohm loads but Ampeg say it's 'ok' to run into 8 as well?

[umph]

[quote name='ste_m3' post='263998' date='Aug 17 2008, 04:10 PM']Id say,
Yes.[/quote]
tube power amp distortion > solid state, solid state distortion sounds like balls

[jensenmann]

[quote name='molan' post='269070' date='Aug 24 2008, 07:04 PM']That's interesting about leaving the power amp tubes out - what does this do to the power output in terms of wattage?

As you're obviously a bit of an expert on Ampegs I wondered what you thought about running the SVTII into an 8ohm cab. I've read that it really prefers to run into 4 or 2ohm loads but Ampeg say it's 'ok' to run into 8 as well?[/quote]

There´s 3 pairs of 6550 or KT88 in the poweramp which work together. Each pair delivers roughly 100W. Leaving out one pair means you get 100W less. But you have to pull a pair that works together. You´d better not pull any two tubes (unless you want it to sound different-it might sound unpleasing). Having said that I remember a gig when I had three dead tubes inside. The band was wondering what´s going on but I enjoyed the biggest fuzzbox ever.

There´s no problem to run the SVTII with 8Ohm. There´s never a problem - technically spoken - to use speakers with higher impedance than recommended for the amp. BUT: The sound changes. The output transformer of any guitaramp or bassamp is - well - underdimensioned. If you push full power into the iron it saturates and generates quite an amount of distortion. For HiFi they use much bigger transformer to avoid this, but musical instrument amplification is a different beast, it benefits from distortion because this colours and alters the sound. We want that :-) Now full power means that you have to use a cab that allows the amp to send maximum current with maximum voltage into the speakers. That´s what nominal impedance is meant for. If you use 8 Ohm instead of 4 Ohm (nom. imped.) cabs then you still have a lot of output voltage from the amp but the current is lower and current is what saturates the ironcore of the transformer. This means you get less distortion and less colouration. You don´t do no harm to neither amp nor cab but your ears will probably detect the difference (unless you use two turbo Rat pedals in series anyway)

Hope this helps