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#1 2012-01-31 15:23:55

buffalo915
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From: El Paso
Registered: 2011-01-20
Posts: 19

Ampeg v2 tube sound

Ok to start off I have an Ampeg v2 that I think isnt running at %100 the reason im saying this is because everyone says how loud they are but mine doesnt seem that loud... I so know that the amp has been modded so that the master has been converted to an attenuator. Also i dont know if this is common but when on standby the amp has a faint hum. I thought it was maybe the tubes so i replaced the power tubes with the new JJs. they sound alright but im wanting a little more head room. So i ordered a set of 6550s to try out. Im planning on taking the head in to get looked over and biased for the set. Im wondering how the 6550s will change the tone of the amp especially when pushed. Also im wondering if there is anything that might be causing the volume drop, i kinda want to have an idea of what to look for before i take it in. Last place i took it to took my money and didnt do much of anything other than replace 1 preamp tube and take 2 months to do so. i dont want to get taken again haha. Thanks!

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#2 2012-01-31 19:17:17

hangman
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From: Seattle Washington
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Posts: 1848

Re: Ampeg v2 tube sound

The kt-88 is really the better choice for the v-2.   6550 has a rated maximum screen voltage of 350,  th v-2 exceeds this by 200 volts.   
With kt-88s the v2 sounds like a monster.   Gives it a more muscular feel.  I think the amp sounds better this way.   
Remember to change the bias and the scree n resistors!

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#3 2012-01-31 19:30:00

buffalo915
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From: El Paso
Registered: 2011-01-20
Posts: 19

Re: Ampeg v2 tube sound

Bummer, I already ordered the 6550s. It's a magnavox v2 its like the one up top but a v2. So would it be bad to use the 6550s?

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#4 2012-01-31 22:41:12

hangman
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Registered: 2006-09-03
Posts: 1848

Re: Ampeg v2 tube sound

if it is a distortion model,  it would be just fine.   

its its the master volume version 6550s work... but i just don't think its the best option.

I have used 6550s in v4s and v2s,  and they work,  but the kt88 will last for ages.

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#5 2012-01-31 23:00:29

buffalo915
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From: El Paso
Registered: 2011-01-20
Posts: 19

Re: Ampeg v2 tube sound

yea its a master volume version, so maybe ill try and trade my 6550s for kt88s

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#6 2012-02-01 02:23:59

hangman
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Posts: 1848

Re: Ampeg v2 tube sound

Yeah, you won't regret it.

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#7 2012-02-01 22:55:30

buffalo915
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From: El Paso
Registered: 2011-01-20
Posts: 19

Re: Ampeg v2 tube sound

I did some reading and some people are saying that the kt88 has really harsh breakup. Is that something to be worried about? Also the tubes I got say 6550/kt88 on the website. They're tungsol, but only say 6550 on the tubes so I'm a little confused.

Last edited by buffalo915 (2012-02-02 09:33:13)

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#8 2012-02-02 17:52:55

hangman
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Re: Ampeg v2 tube sound

I don't know what your friends are talking about.  If they mean that the kt-88 has a more abrupt breakup than the 7027 that is true.... But harsh?  No way.  They make the v2 sound bigger if anything.

The kt-88 and 6550 are similar tubes but definitely not the same thing.  But the 6550 has a maximum screen voltage of 350v. While the kt88 has a max of 600v.   Big difference.

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#9 2012-02-02 23:34:31

buffalo915
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From: El Paso
Registered: 2011-01-20
Posts: 19

Re: Ampeg v2 tube sound

hey thanks for getting back to me and answering my questions. That being said anyone looking to trade a matched pair of tungsol 6550s for a matched pair of kt88s?

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#10 2012-02-25 19:45:08

buffalo915
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From: El Paso
Registered: 2011-01-20
Posts: 19

Re: Ampeg v2 tube sound

http://www.youtube.com/watch?v=DoucXCsy … ata_player

Here's a video of my amp. It has been modded for kt88s. I'll be picking it up on Monday

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#11 2012-02-26 05:41:35

nitraus
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Registered: 2012-02-22
Posts: 55

Re: Ampeg v2 tube sound

hangman wrote:

The kt-88 and 6550 are similar tubes but definitely not the same thing.  But the 6550 has a maximum screen voltage of 350v. While the kt88 has a max of 600v.   Big difference.

How does it translate sonically speaking? My V4 now has 6550s in it, how would it sound with KT88s?

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#12 2012-04-16 02:28:34

Gabry
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Re: Ampeg v2 tube sound

hello forum,

Anyone ever try the V2 with KT66's?

I have the master volume version (plastic knobs -> late 70's?) with 7027's. I use it for guitar. Allthough it's possible to get break up from the 7027's, achieving it at a reasonable volume is not. Perhaps if I had a less efficient speaker, but that's not the case. Also, the breakup I do get is not very smooth. So instead I overdrive the 12ax7's (JJ's) in the pre-amp. It's allright, but still a bit brittle, a bit too harsh, not very smooth. I really like the enormous range and EQ possibilities on this amp but I am not really sure if this type of tube break up is for me. Would a KT66 have a smoother and earlier (less wattage than 7027) break up?

Thanks in advance,
Gabry

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#13 2012-04-16 07:56:41

Liquids
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From: CT
Registered: 2010-08-01
Posts: 491

Re: Ampeg v2 tube sound

Not a bad idea.  The KT66 are big base tubes so you'd need to eliminate the clamps and go for spring retainers.

Aparently the KT66 break up nicely - some say milkshake thick, some say grainy...you'll have to determine.

JJ KT66 says it can take 550v on plate and screen, so running the V2s 590v may not be unreasonable...so long a you know the risks. They are 25 watt tubes to a 6L6s as a 30 watt tube.

your 7027s may be poorly matched and MAY be clipping very asymmetrically as a result, which often results in what to me is a ratty tone, in a tube power amp.

Do you hate EL34s or something?  Those would be a reasonable choice if you want breakup...most people like how El34s break up.

Otherwise, you may just have the wrong amp for trying to get breakup you like at reasonable volume.


Matthew

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#14 2012-04-24 13:42:11

Gabry
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From: Nederfuckingland
Registered: 2010-03-22
Posts: 7

Re: Ampeg v2 tube sound

thanks Liquids.

I run my guitar into two amps, a 50 watt Hiwatt (EL34s) with master volume almost at max. The EL34s in the hiwatt are great. So, no hate there. I wanted to see if I could add some interesting lows by adding a different type of amp and cab. The V2 (into an EV15L) is certainly cappable of that. But getting it with a nice overdriven sound from the tubes is not as easy.

Keeping the pre at a relative low level and cranking the poweramp works very well with the Hiwatt and results in very nice controllable break up sound from the EL34s. With the V2, also a master volume model, this wont work. Its probable the type of circuit but its always too loud if I use it that way. Always. And Im certain the tubes are matched properly. Id like to know if switching to a different tube would make much of a difference in that regard. I suggested the KT66 based on info from the 7027-link on the front page where it says you can pop in KT66s without any modifications. Anyway, thanks for chipping in liquids. Perhaps KT88s, as suggested earlier in this thread, and a decent pedal are the way to go with this amp.

Last edited by Gabry (2012-04-24 13:44:49)

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#15 2012-04-25 04:32:08

Liquids
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From: CT
Registered: 2010-08-01
Posts: 491

Re: Ampeg v2 tube sound

I'm not as familiar with the master volume models, and there may be more than one?

Two other options given that I am shooting from the hip and will ask schematics later -

Aren't there two channels on your amp?  Some of the distortion models use diode clipping in there somewhere if I'm not mistaken...and if you are using that model/channel, that may be something you're not liking and part of the "but still a bit brittle, a bit too harsh, not very smooth."  I think that on the master volume or distortion models, the second channel is more the 'classic' V-series sound and more likely to be pleasing for what your trying to do

1) if there is a rocker switch for 'sensitivity' make it the loudest one, or at least expiriment with it in different positions...you are literally be configuring the gain/negative feedback around that first tube stage in the amp, and it can make a significant difference in tone if you are at/on the edge of breakup, both tonally, and at what volume that happens.

2) get a clean boost pedal...not all that are touted as such are truly clean...but even a small about of TRUE clean boost.  Op amps based pedals are IMO the best and truest means, though if you want some EQ shaping there are other options, I'd go for the visual sound product for various reasons I'll not explain unless asked. This would allow you to come out of the gate with a really hot signal slamming into that first tube, as close to causing it to breakup/distort/clip as you like, and outside of a 'volume' control between tube stages, if your first tube is clipping or near it, the next one and all forward are too...so it allows you more possibilities for breakup and cascading.

However, if you go for a clean boost, and the circuitry you are running through is the classic V series preamp-power amp only with an added master volume....I'd say yeah, for one, at least upgrade the tone stack.  IMO (I've posted this elsewhere) the treble cap VALUES (there are two) are too big in this preamp and can be made smaller so they affect high-midrange LESS and just the highs MORE, which causes less ear fatigue. You have control of high-midrange if you want it via the active midrange+ rocker switch anyway!!!

Otherwise, yes power tubes are a good thing to play with. I totally get that if you are running it alongside an EL34 Hiwatt, you'd be shy about making your V-series run EL34s.  I still think it would be different and fatter - the preamps and EQ control are totally different, that alone might add the difference and I sure find the V series has unique and interesting lows, though I've not played a Hiwatt.  Part of the hiwatt is the EL34s, but if somehow your hiwatt conveniently had a preamp out/power amp in jacks in the same configuration as the V series, it would be very educational to hear one preamp driving the other's power amp, to isolate some of the variables...

I'm sure you've gone here already, but be aware of what preamp tube brands you are using.  If you want/like fat breakup rather than the adjectives you used, I'd tend toward using current production tung-sol 12ax7s where possible.

Also it would help (us and you) to know how your amps are and end up biased...but there is a LOT you can do to take a great amp like this and tweak it to perfection for the tone your after if you're a little patient, and have a little money & a good tech, or are handy and safe at the workbench yourself.


Matthew

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#16 2012-04-25 12:30:44

hangman
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Posts: 1848

Re: Ampeg v2 tube sound

Wait...You like amp,  but you dont like that it doesn't breakup until its loud,  and once it does you don't like the breakup?

Are you sure you like the amp?

Using kt66 or kt88 won't really change much in terms of how loud it is when it starts to breakup.   If anything it will make it a little cleaner.

I would say don't get too carried away trying to make the v2 into the amp you want it to be.  Rather try to utilize it in a way tat gets you to the place you want to be ( liquids' boost pedal suggestion,  or Even a THD hot plate)

I do agree that Replacing the integrated tone stack circuit with discrete parts make worlds of difference in the quality of the highs and roundness of the lows,  but the overall character of the amp doesn't change.   

Just my thoughts

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#17 2012-05-10 08:28:01

Liquids
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From: CT
Registered: 2010-08-01
Posts: 491

Re: Ampeg v2 tube sound

If the KT88s reach breakup at an abrupt point, the feedback resistor can be increased so that it is different and more gradual breakup.  There are good articles at aiken amps on this.

Steve - what KT88s do you recommend?  I have a slew of 6L6s to 'burn through' but I find a pair of KT88s enticing in part for the tone (and dead clean only) but more so for longevity.  But they're expensive.  I'd only get a pair - what brands do you recommend and discourage here?


Matthew

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#18 2012-05-10 08:45:35

Liquids
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From: CT
Registered: 2010-08-01
Posts: 491

Re: Ampeg v2 tube sound

Actually, if the KT88 is generally high headroom but has abrupt breakup, removing the feedback altogether is another option - might be a good starting point...if it's too much of a tonal change, start large (1M) with the feedback resistor, and get smaller till the balance between gradual breakup with the KT88s and the tone you want is achieved.


Matthew

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#19 2012-05-10 08:56:58

hangman
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Posts: 1848

Re: Ampeg v2 tube sound

Do not use the JJ kt88.  They blow up.   We've had so many of them short after very few hours of moderate use.   I trust the winged c first and foremost,  and the svetlana is good.

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#20 2012-05-10 09:27:17

Liquids
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From: CT
Registered: 2010-08-01
Posts: 491

Re: Ampeg v2 tube sound

EHX, Sovtek, even Valve Art are available from tubesandmore, at a decent price.  Are they junk?

The Winged C just came out but you've been touting KT88s for a long time.

I can't find Svetlana Kt88s.


Matthew

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#21 2012-05-10 11:21:13

hangman
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From: Seattle Washington
Registered: 2006-09-03
Posts: 1848

Re: Ampeg v2 tube sound

Can't speak for the sovteks.   Ive heard good things about the EH and have used them in a few amps,  but dont have enough experience with thm to give them two thumbs up.

Valve art.... Never bothered.

The winged c kt88 has been my go to for many years.

As for the svets I can't say where to find them online... We get them strait from new sensor.

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#22 2012-05-10 12:32:30

Liquids
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From: CT
Registered: 2010-08-01
Posts: 491

Re: Ampeg v2 tube sound

Sorry, I was thinking of JJ and their recently produced 6550s.

I wouldn't be surprised if the EHX branded Kt88s were the Svetlanas.  From the new sensor website, they look quite similar outside of the envelope being a little different.  May at least the same factory - both are new sensor. The Sovtek look completely different however (and also new sensor).

Does the KT88 hit the transformer in the socket closest to it, on a V4?  Or can two Kt88s fit and not touch each other if they're in the center sockets of a V4?

Last edited by Liquids (2012-05-10 12:32:50)


Matthew

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#23 2012-05-10 17:26:27

hangman
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From: Seattle Washington
Registered: 2006-09-03
Posts: 1848

Re: Ampeg v2 tube sound

Using the kt88 in the v4 is problematic.  It does get really closetothepower transformer....like mm away.
For that reason i tend to shy away from  usingt hem in the v4.  I recommend them for the v2 however.

I wouldn't be surprised if the svets were eh.   Might just be marketing for the US.   Their website says they can't ship to Europe... Prolly due to the trademark issue with SED

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#24 2012-06-04 08:56:33

Liquids
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From: CT
Registered: 2010-08-01
Posts: 491

Re: Ampeg v2 tube sound

So you generally recommend V4 owners to use Winged C 6L6GCs in quads or pairs as the best bet?

I had thrown out the idea of wiring up a V4 for a quad of current production 7591s as an option for some.  Obviously less output, but there's plenty to spare and some people might like that if it can handle it.  Maybe even a pair?  What do you think of that? When I asked I think I had checked the plate and screen voltage specs....I don't intend to do that, just curious and put it out there at some point.

Likewise, I haven't taken my chassis out of it's cab for a while but I've been running just 2 6L6GCs in my V4 (the cheap sinos as often mentioned) with the re-setting of the speaker impedance switch factored, but never checked the plate voltage, I confess, in embarassment....those sinos are cheap and I just wanted to try and see if they fry.  They didn't fry, and it's been on the to-do list to open her up and read some voltages, thinking that B+ may have been raised overall with 2 less plates and grids pulling current but...well...it's been on that list for months, and still is.....

I lost one of that quad of tubes to intermittent  redplating when they were running as pairs...but in the end, I just threw another of the well match cheap sino quad in there and it carrys on....

Anyhow, am I wrong to assume plate voltage has probably risen on the power tubes, running 2 instead of 4 in the V4? In your experience and knowledge, should I expect that my bias voltage has been affected by pulling two tubes?  Has the overall B+ (affecting the PI and preamp tube voltages) possibly been shifted upward from using only 2 power tubes in the V4?  I'm not concerned about the preamp voltages - I think they could be much much higher anyhow, but, you know a lot more than I do and I haven't actually measured.

Last edited by Liquids (2012-06-04 08:57:46)


Matthew

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#25 2012-06-11 17:00:31

Liquids
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From: CT
Registered: 2010-08-01
Posts: 491

Re: Ampeg v2 tube sound

Steve - would love your take on the above.


Matthew

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