Ampeg SVP CL preamp question

[JJR58]

SVP-CL is the exact preamp from an SVT. It sounds great. But the power tubes and output transformer are huge parts of the equation as well, and just the preamp doesn't sound quite as rich and tubey.

And I most certainly agree with you Mr. M.
But I gotta tell ya, this hair brained set up sounds pretty good. As far as this nuttiness goes, keep the GK pre gain at 9'O'clock. And have at it with the SVP. My problem with the GK is, it sounds like plastic on its own, no offense to GK. But the Ameg pre gets rid of that.

 

[mc900ftj]

That is a great combo! IMO, better sounding and can be pushed harder than most standalone class D bass amps.

I often pair it with this cab, as shown here...

 

[Bass 45]

Which is this? Original?
Ampeg SVP Black with White Controls

Looks like an early or prototype SVP-Pro (serial number "A"!).

 

[ThisBass]

Schematic wise the different preamps belong to svt heads as follows:
SVT-IIP => SVT II
SVP-CL => SVT CL
SVP-Pro => SVT II pro

As far as I know there was never released any preamp based on SVT respectively SVT-VR

Personally prefer to use the SVT II pro schematic drawing for service on my SVP-Pro due to better outline of the signal path etc. cause the original SVP-Pro schematic drawing seems like junk that is hard to read.

 

[Dave Hill]

Schematic wise the different preamps belong to svt heads as follows:
SVT-IIP => SVT II
SVP-CL => SVT CL
SVP-Pro => SVT II pro

As far as I know there was never released any preamp based on SVT respectively SVT-VR

Personally prefer to use the SVT II pro schematic drawing for service on my SVP-Pro due to better outline of the signal path etc. cause the original SVP-Pro schematic drawing seems like junk that is hard to read.

SVP CL is NOT from the SVT CL. It is almost identical to the 70's SVT except for some sort of tube substitution.

 

[Dave Hill]

The SVP-CL is ONE CHANNEL of the original SVT pre, using sections of 12AX7 and 12AU7 to replace the harder to get 12DW7 and 6C4 tubes. The 12DW7 was half one and half the other, so it makes sense.

The SVT-CL is different from either the SVP-CL or the original SVT.

Yes it is quite confusing, which I told them it would be.....

 

[ThisBass]

SVP CL is NOT from the SVT CL. It is almost identical to the 70's SVT except for some sort of tube substitution.

Schematic wise most close to 70's svt in descending order:

- svt IIp (nearly identical except some minor assimilation to substitude ECC83 stage (buffer) for ECC82 stage (buffer))
- svp CL (additional filters for bass boost/cut and bright switch)
- svp pro (which can be considered as an widely independent design)

 

[Dave Hill]

Schematic wise most close to 70's svt in descending order:

- svt IIp (nearly identical except some minor assimilation to substitude ECC83 stage (buffer) for ECC82 stage (buffer))
- svp CL
- svp pro (which can be considered as an widely independent design)

Sorry I'm going with @Jerrold Tiers. Read his quote above.

 

[ThisBass]

I'm


Sorry I'm going with Jerrold. Read his quote above.

And I'm going with reading schematic drawings

 

[Bass 45]

I have a question - since it seems like there are people here that know a lot about these Ampeg pre-amps.

My SVP-Pro shutdown on me during a gig a couple weeks ago - there is no power now - not even a power indicator light. I used a multi-meter to see if voltage was passing through the fuses and it is. I noticed that on the transformer it reads "Thermal Fuse Built In" - I was hoping it would reset or something after cooling down - but it has not. Is there any way to replace or reset the fuse?

I called Ampeg and inquired about a replacement transformer - but they no longer have any.

I think I saw somewhere on TB that somebody else had a similar problem but I don't remember where, or if there was a conclusion.

Thanks

 

[TheRealKong]

Another SVP Pro - user here. A long time I used a Class-A/B - poweramp with the preamp, and I loved it. As said more than one time, not as tubey as the "real deal", but used Ampeg zube-amps are not easy available in Germany. And new ones sure do cost some dough.

running it through the front of a GK700RBii

I canged the poweramp last year to a real powerfull Class H - amp, 2 x 350 Watt RMS @ 8 Ohm, 2 x 500 RMS Watt @ 4 Ohm, 2 x 520 Watt RMS @ 2 Ohm, 800 Watt RMS bridged @ 8 Ohm and 1000 Watt RMS bridged @ 4 Ohm. Class H is the same design GallienKrueger does use in the RB - Series.

The Class A/B - poweramp had about 40 lbs. But the Class H is only 18 lbs. And it has a kind of a breakup when the preamp comes in with some power. Its like the GK - growl the 400 RB is able to give you with the input stage driven hard. Maybe you have the same feel with your 700 RB II.

When I use it with only one side of the poweramp into a sealed 410" - cab @ 8 Ohm that is designed like an Ampeg 810" "Flatback", cut in half, the sound is killer! I bet you could not say if it is a pre- + poweramp solution or the "real deal".

This sealed cab was built by a local musicstore about 30 years ago, because of the weight of the 810" - and the price. It is a perfect match with my V4b Ri.

To have a more modern but SVT - like sound I use a tecamp L 810" @ 4 Ohm, the poweramp is bridged, power and SPL for weeks! I play this rig in a heavy metal band for several years, and never looked back. I have a second L 810" for another band, and I would love using both cabs with that rack. I am waiting for the open air season.

Btw, I have a Bugera BVV 3000 that is, as people say, a reverse engineered SVT CL. And an Ampeg V4b Ri. And I love this two amps. So I think I can say that I know something about "Ampeg Sound".

 

[bhoff5150]

I have an SVT-CL and a V4B. The all tube power section in both are awesome. I am currently in the middle of an experiment. I'm attempting to get the all tube sound of either head in a lighter weight package. I have gone through every preamp known to man, and some of them get really close but not quite there. I have found my favorite preamp, the SVT-IIP (non-pro) preamp. I like it better than the SVP-Pro, etc etc......

I just acquired a Demeter Minnie 800D and paired it with the SVT-IIP preamp at home. It does sound very very good. I will take it to band practice this week and compare it with my SVT-CL that I use at band levels. My fingers are crossed, but so far everything I have tried has not replaced my 90 pound SVT-CL or V4B.

I'll post back after I try this setup at full volume.....

Test results in from last night's practice. The Ampeg SVT-IIP preamp into the Demeter Minnie 800D is the best, most authentic sounding lightweight package I have found. I have gone on a 5 year "gear journey" attempting to find a lightweight replacement for my SVT. This combination is the closest I have found. It sounds good, really good. However when I switched back to the SVT about halfway through band practice, alas, it is not the same. The SVT has a little more sonic goodness (for lack of a technical term). The sound is just "fuller" out of the 300W, 90 pound SVT than the 800W 3.5 pound class D power amp.

I finally give - you cannot replace the sound and tone of the SVT. I will lug that heavy mother around as long as my back can take it. For those of you who looking to lighten up your rig for back issues or convenience, I would certainly take a look at this power amp paired with your favorite preamp.

 

[Raw N Low]

Test results in from last night's practice. The Ampeg SVT-IIP preamp into the Demeter Minnie 800D is the best, most authentic sounding lightweight package I have found. I have gone on a 5 year "gear journey" attempting to find a lightweight replacement for my SVT. This combination is the closest I have found. It sounds good, really good. However when I switched back to the SVT about halfway through band practice, alas, it is not the same. The SVT has a little more sonic goodness (for lack of a technical term). The sound is just "fuller" out of the 300W, 90 pound SVT than the 800W 3.5 pound class D power amp.

I finally give - you cannot replace the sound and tone of the SVT. I will lug that heavy mother around as long as my back can take it. For those of you who looking to lighten up your rig for back issues or convenience, I would certainly take a look at this power amp paired with your favorite preamp.

Imitated but, never duplicated. I would love to try the (Insert Ampeg Pre) into a Minnie 800 but, for the cost of the Minnie and an Ampeg pre, you could get an actual SVT head. Good to see amps going in the small 1u direction.

 

[Raw N Low]

Another SVP Pro - user here. A long time I used a Class-A/B - poweramp with the preamp, and I loved it. As said more than one time, not as tubey as the "real deal", but used Ampeg zube-amps are not easy available in Germany. And new ones sure do cost some dough.



I canged the poweramp last year to a real powerfull Class H - amp, 2 x 350 Watt RMS @ 8 Ohm, 2 x 500 RMS Watt @ 4 Ohm, 2 x 520 Watt RMS @ 2 Ohm, 800 Watt RMS bridged @ 8 Ohm and 1000 Watt RMS bridged @ 4 Ohm. Class H is the same design GallienKrueger does use in the RB - Series.

The Class A/B - poweramp had about 40 lbs. But the Class H is only 18 lbs. And it has a kind of a breakup when the preamp comes in with some power. Its like the GK - growl the 400 RB is able to give you with the input stage driven hard. Maybe you have the same feel with your 700 RB II.

When I use it with only one side of the poweramp into a sealed 410" - cab @ 8 Ohm that is designed like an Ampeg 810" "Flatback", cut in half, the sound is killer! I bet you could not say if it is a pre- + poweramp solution or the "real deal".

This sealed cab was built by a local musicstore about 30 years ago, because of the weight of the 810" - and the price. It is a perfect match with my V4b Ri.

To have a more modern but SVT - like sound I use a tecamp L 810" @ 4 Ohm, the poweramp is bridged, power and SPL for weeks! I play this rig in a heavy metal band for several years, and never looked back. I have a second L 810" for another band, and I would love using both cabs with that rack. I am waiting for the open air season.

Btw, I have a Bugera BVV 3000 that is, as people say, a reverse engineered SVT CL. And an Ampeg V4b Ri. And I love this two amps. So I think I can say that I know something about "Ampeg Sound".

I often pair one of my SVP Pro with my SVT 6pro. Very deep sounding with aggressive mids. Especially from two 410he's

 

[Danjoman]

sounds

 

[Gary Stevens]

I use QSC power amp with my SVPCL with great results. Yesterday, I put a Fulltone clean boost in frint of the preamp since I use early 60s Fender low output passive pickups