NAD: 1970's(?) Ampeg V-4 Magnavox

[Raw N Low]

I'm super excited and have been waiting a few days to pick up this baby. I know it's late 70's but, I will need to open her up to see the date. Excellent condition for the year and sounds great to boot. Couldn't be happier.

Looks like it still has NOS Magnavox 7072's it still. Should I pick up a new set as not to wear these out? I plugged it into a sealed Ampeg 15 and then a sealed 410. Sounds great and had alot of punch playing on the A string. I noticed that lows kinda cut out on the closed E. Anybody have any tips on how to remedy that? Should I try pairing it with 412's?

I'm just giddy!

It was a coin toss between this amp and an American Peavey Cirrus. I now know I made the right choice.

 

[JimmyM]

If it's cutting out at all, I would take it to a tech who knows vintage Ampegs and have him/her look at it just in case it's a larger issue. As for the power tubes, I'd wait and see if they're still working properly before I made any decisions. Looks pretty clean, though...I'm sure it'll be a kickass amp for you!

 

[Raw N Low]

If it's cutting out at all, I would take it to a tech who knows vintage Ampegs and have him/her look at it just in case it's a larger issue. As for the power tubes, I'd wait and see if they're still working properly before I made any decisions. Looks pretty clean, though...I'm sure it'll be a kickass amp for you!

Thanks Jimmy, I'm very happy with it. I should re-phrase that it's not cutting out, just not as much punch or lows on the bottom E string. I will have a local Ampeg tech give it a good look over. I heard that some people mod the V-4's with larger caps to get the bottom of the V-4B. Would this be something worth looking at?

 

[JimmyM]

Thanks Jimmy, I'm very happy with it. I should re-phrase that it's not cutting out, just not as much punch or lows on the bottom E string. I will have a local Ampeg tech give it a good look over. I heard that some people mod the V-4's with larger caps to get the bottom of the V-4B. Would this be something worth looking at?

You would hae to ask someone with more knowledge than me. I just play them as they sit and never tried that. However, if you're not getting as much low out of the low notes, I would suspect something wrong.

 

[johnpbass]

Congrats, very nice! Clean - even the graphics are in super shape!

 

[beans-on-toast]

Thanks Jimmy, I'm very happy with it. I should re-phrase that it's not cutting out, just not as much punch or lows on the bottom E string. I will have a local Ampeg tech give it a good look over. I heard that some people mod the V-4's with larger caps to get the bottom of the V-4B. Would this be something worth looking at?

Oh man is that amp ever clean, you really found a nice one.

I can't tell from your images if the power supply electrolytic caps are original or not. When they start to go, the first thing you notice is that the lowest notes are not reproduced well. You loose headroom and eventually distortion sets in. This could be the reason why you are noticing a problem with the bottom E string.

I wouldn't be in a hurry to increase the power supply capacitance. Although I have to admit to doing it in my '74. I use it as an experimental platform so I am open to mods on it.

The amp should have an internal cleaning and close inspection. All metal to metal contacts such as jacks and tube socket terminal should be scrubbed with deoxit. The V4(B) runs hot and it can take a toll on the solder joints. They should be checked and reflowed as necessary. Voltage readings need to be taken and compared to references on the schematic to ensure that the power supply is performing up to spec. A tech can determine if the amp needs the power supply caps changed. The tubes need to be checked, they could be worn down. It is important to have the power tube bias checked.

It is true that matched sets of NOS 7027's are getting harder to find. If your tubes check out well and you want to preserve them, there are new production ones available. I'm running a set of Tung-Sol 7581A's in my amp and am very happy with their performance (www.thetubestore.com - Tung-Sol 7581A Audio Tubes).

 

[Raw N Low]

Oh man is that amp ever clean, you really found a nice one.

I can't tell from your images if the power supply electrolytic caps are original or not. When they start to go, the first thing you notice is that the lowest notes are not reproduced well. You loose headroom and eventually distortion sets in. This could be the reason why you are noticing a problem with the bottom E string.

I wouldn't be in a hurry to increase the power supply capacitance. Although I have to admit to doing it in my '74. I use it as an experimental platform so I am open to mods on it.

The amp should have an internal cleaning and close inspection. All metal to metal contacts such as jacks and tube socket terminal should be scrubbed with deoxit. The V4(B) runs hot and it can take a toll on the solder joints. They should be checked and reflowed as necessary. Voltage readings need to be taken and compared to references on the schematic to ensure that the power supply is performing up to spec. A tech can determine if the amp needs the power supply caps changed. The tubes need to be checked, they could be worn down. It is important to have the power tube bias checked.

It is true that matched sets of NOS 7027's are getting harder to find. If your tubes check out well and you want to preserve them, there are new production ones available. I'm running a set of Tung-Sol 7581A's in my amp and am very happy with their performance (www.thetubestore.com - Tung-Sol 7581A Audio Tubes).

Thanks Beans. I will have it checked out by a tech. It may be a little while as I'm getting another amp serviced as of now. Thanks for the reference on the power tubes! I will pick up a set ASAP to try to preserve the 7072's (if they are still good).

The guy I bought it from, said that he would attach a little fan to the back to stave off the heat that this amp would produce. I was told that once he had the amp biased, that he hadn't played it in three years. The seller is a guitar player and when he demo'd the amp, my ears started to bleed. On guitar this thing is loud, and that was through a single Ampeg 12.

Do you know what is an optimal and effecient cab to run with this amp? Is the V4 cab or Sun 412L a good cab to pair for practice room bass?

Overall, I couldn't be happier. Vintage or semi vintage Ampeg gear is getting harder and harder to find in good condition.

 

[beans-on-toast]

Finding the right cab for a V4 might be a good thread to start.

The amp is wider than most so finding a cab that it fits on can be a challenge. It sounds good through everything that I've tried including an 810 and 412. I normally use a pair of EV 115 PA cabs, similar to a TL606 in design.

There have been some threads on TB discussing what cab goes well with a V4. As you can imagine, there are many suggestions. I imagine that an Ampeg SVT-212AV would pair well for a practice room. This cab sounds good with many different amps.

Ampeg SVT-212AV | SVT Bass Cabinet


People have picked up older V4 cabs and changed out the speakers:
Ampeg V4 - 4x12 Cabinet - Speaker Suggestions

 

[Joe Ty]

I'm super excited and have been waiting a few days to pick up this baby. I know it's late 70's but, I will need to open her up to see the date. Excellent condition for the year and sounds great to boot. Couldn't be happier.

Looks like it still has NOS Magnavox 7072's it still. Should I pick up a new set as not to wear these out? I plugged it into a sealed Ampeg 15 and then a sealed 410. Sounds great and had alot of punch playing on the A string. I noticed that lows kinda cut out on the closed E. Anybody have any tips on how to remedy that? Should I try pairing it with 412's?

I'm just giddy!

It was a coin toss between this amp and an American Peavey Cirrus. I now know I made the right choice.

Nice, doesn't look like she ever saw the road.

 

[xJasonSmithx]

Looks great! I have the V4B Reissue and I also live in Denver! Was that the one posted on CL here?

 

[xJasonSmithx]

There is an Ampeg B-40 cab on Craig's List that might be a good match for it. I believe that is one of the wider 4x10 cabs that would look correct under your head.

 

[Raw N Low]

Looks great! I have the V4B Reissue and I also live in Denver! Was that the one posted on CL here?

Yes it was! The seller was from Boulder. I was shocked to see it was posted for almost a month at the price he asked for. The other two were worse off cosmetic, and priced higher. I will check out the other Ampeg cab.

There is a Sunn 412L near Morrison I'm really curious about.

 

[40Hz]

I now know I made the right choice.

That comment is in the running for understatement of the year.

Finding a Magnavox era V-4 in that condition is a once in a lifetime score. Rock it well!

 

[Roxbororob]

Thanks Jimmy, I'm very happy with it. I should re-phrase that it's not cutting out, just not as much punch or lows on the bottom E string. I will have a local Ampeg tech give it a good look over. I heard that some people mod the V-4's with larger caps to get the bottom of the V-4B. Would this be something worth looking at?

I'm super excited and have been waiting a few days to pick up this baby. I know it's late 70's but, I will need to open her up to see the date. Excellent condition for the year and sounds great to boot. Couldn't be happier.

Looks like it still has NOS Magnavox 7072's it still. Should I pick up a new set as not to wear these out? I plugged it into a sealed Ampeg 15 and then a sealed 410. Sounds great and had alot of punch playing on the A string. I noticed that lows kinda cut out on the closed E. Anybody have any tips on how to remedy that? Should I try pairing it with 412's?

I'm just giddy!

It was a coin toss between this amp and an American Peavey Cirrus. I now know I made the right choice.

Oh you made the right all right. Very envious up here. Dream amp. Enjoy!

 

[LosFer Words]

Not sure what your volume needs are but the V4B sounds glorious through an 810. When I joined a Celtic band I got a couple of SVT210's...similar sound but a much lighter package.

 

[Raw N Low]

Not sure what your volume needs are but the V4B sounds glorious through an 810. When I joined a Celtic band I got a couple of SVT210's...similar sound but a much lighter package.

My area is in severe shortage of really good 810's and even 210's made by Ampeg. I would love to have an 810 just to pair with my SVT II Pro. I bet a couple of 210's would sound killer with the V4.

I played some Thin Lizzy covers with the V4 and my T-40. I had the flanger pedal out and I was grinning from ear to ear. Seriously a killer amp.

 

[JKB1957]

Very nice. Good luck with her. Keep the groove.

 

[Artobass]

Great amp! Congratulations! I'll never part with mine.

 

[beans-on-toast]

My area is in severe shortage of really good 810's and even 210's made by Ampeg. I would love to have an 810 just to pair with my SVT II Pro. I bet a couple of 210's would sound killer with the V4.

I played some Thin Lizzy covers with the V4 and my T-40. I had the flanger pedal out and I was grinning from ear to ear. Seriously a killer amp.

That what road trips are for, they can be a lot of fun. It's nice to have a purpose if you are going on a long drive. Otherwise, take advantage of free shipping to your location. Finding the funds, that another story.

 

[two fingers]

Great amp!

There is a fantastic thread around here somewhere that covers in detail the differences between a V4 and V4B. That would be something to look into for sure. I had one for a while. I don't regret passing it on (I swap oht stuff alk the time) but it's one of the few pieces of gear I really look back on fondly.