Wednesday, December 8, 2010

Comparison: Kalamazoo amp vs. VHT Special 6

Once again, here is the video of Nic Clark playing the modified VHT Special 6 amp:

Here are three links to Youtube videos of the Kalamazoo amp:

Kalamazoo model 1 blues harp amp

custom kalamazoo harp amp model 1

Kalamazoo amp and BluexLab harp mic

The Kalamazoo amp suffers from a design that gives it that raspy harsh tone: It uses a single EL84 power tube, while the VHT Special 6 amp uses the warmer sounding 6V6 power tube. The 6V6 was the tube used in many classic harp amps from the glory days of tone… Amps such as the Fender Champ and Princeton, vintage Gibson amps, the National/Supro amps, the classic Premier amps like the Twin 8, and cool old PA amps like the Newcomb E-10B.

I cannot think of any classic harp amps that used a single EL84 tube. The EL84 has a characteristic tone that I call a “crackly mush.” The tube has a very low negative bias voltage, so the tube is driven to square wave distortion very easily. I wrote about the details of this problem here: EL84 Harp Amps.

The 6V6 tube has a much warmer tone and smoother distortion, which is why it was the choice of so many of the great blues harp players of the 50s.

The Kalamazoo amp has been popular as a low cost practice amp for harp players. One particular vendor rehabs these old amps and sells them for $269 for a “beat up Model 1,” and up to $379 for a “really clean Model 2.” No matter which one you buy, you still get and old amp made of particle board that often disintegrates when exposed to moisture.

For less than $200 you can buy a brand new VHT Special 6 whose cabinet is made entirely of finger jointed plywood. Its circuit is soldered point-to-point on an eyelet board, and it is guaranteed for 5 years (90 days on speaker and tubes). The amp circuit is essentially a vintage Fender Blackface Champ, with a 10-inch speaker in a larger cabinet.

When bench tested the VHT amp produces an honest 6 watts of power right at the point it begins to clip. It is very loud for a small amp. The Kalamazoo amps produce about 3 watts at the point they begin to clip. Some vendors claim the amps put out 8 or 10 watts, but that is an exaggeration and does not comport with the generally accepted methods of measuring amp power for the purpose of comparison.

Right out of the box the VHT is a much better harp amp than the more expensive Kalamazoo. Its tone is warmer and more dynamic, and much bigger and less boxy. For about the cost of the “beat up” Kalamazoo amp you could purchase a brand new upgraded VHT amp that is among the sweetest I have ever heard.

UPDATE: From Wikipedia - "When overdriven, the EL84 power tubes in these amplifiers produce a distinctive chiming, articulate, treble-heavy sound..." Yep, that's what I hear when harp is played through the Kalamazoo and other EL84 amps.


peter Moore said...

I have been following a number of these VHT posts that have been circulating on Harp forums. I like the premise of buying a cheap 5 watt amp and using it for rehearsals, recording and playing in clubs. The perfect antidote to the discussions that center around the "boutique amps."

Every harp player should own a 5 watt. They are excellent for home practice. They are good for recording when placed in the capable hands of a sound engineer. I use mine for rehearsals. I play w/ a drummer, keyboard, guitar and drummer who all use lo-fi amps and sound levels are never an issue. I have used the amp for small gigs but on the whole I would not use one of these at a gig mic or otherwise as the amp is not as versatile as a larger amp.

I have a Sears Silvertone amp 1672 withe an 8" speakers. I got it for 100$. No mods, no speaker or tube change, it works brilliantly. You can get them on eBay and there is a variety of models. There were a lot of these sold so they are not rare.

I listen to all the clips. They all sound the same to me, they are not lousy, but they are nothing that blows my mind or at the least, surprises and delights me. No, they sound just about what I thought they would.

Now I expected the Nic Clarke one to be heads and tails above the other. Why? Well, that amp cost $200, has a 75$ upgraded speaker, a $15 tube and has spent some time bench labor ($30.00/hour, Mission website) for a total cost of $320. To my ears, there is no difference. I don't see the value spending another $120. At $320, your now it the ball park of a used Blues Jr. or Champ.

Rick Davis said...

You can't hear a difference between the Kalamazoo amps and the VHT? Wow... I hear a dramatic difference. You may prefer the tone of the K-Zoo amps; some people do. But it is hard to believe you hear "No difference."

The VHT amp as played in this video would cost LESS than a clean refubed Kalamazoo amp. A lot less.

Try listening to the K-Zoo amps again. Notice the distortion. It is jagged and raspy. That is because the EL84 power tube in the K-Zoo is easily overwhelmed by a hot signal and starts producing square waves. It becomes a diode: an on-off device. You can hear it.

The distoriton in the VHT (with 6V6 power tube) is nothing like that. The distortion is a smooth tearing along the edges of the notes. The difference is apparent and easy to hear.

Rick Davis said...

Peter, do you have a link to a recording or video of you playing your Silvertone 1672? I've not tried one and I'd like to hear it.

Rick Davis said...

Peter, are you sure you own a Silvertone 1672 amp? I'm unable to find that model.

peter Moore said...

Hi Rick,
The Sears Silvertone I have is a model #1481.
Here is a video I found on youtube of a harp being played through one:


Harpsucker has a video also.

If you are chasing that tone , check out the Silvertones.

I hear no discernible difference between the Kalamazoo and VHT. I mean, nothing that knocks me out. It's a 5 watt amp. And the upgraded one is louder, what 6 watts?

I disagree with your statement "it's a boutique amp at a fraction of the cost." No sir, its a 5 watt amp no matter how much lipstick and powder you put on it.

Rick Davis said...

Ahhh... so it's not a Silvertone 1672, it's a 1481. I'm glad you got that figured out. I am familiar with that amp. We are all entitled to our opinions, and my opinion about the 1481 with it's 8-inch speaker is that it sounds nasal, boxy, shrill, and annoying. It is very under-powered. What kind of speakers do you have connected to your computer? I defies credulity that you cannot hear any difference between that and the VHT Special 6 amp.

Your understanding of "boutique" amps is also odd. There are 5-watt harp amps from boutique builders, such as the fine Harpgear HG2. The HG2 is priced at $820. The modified VHT Special 6 amp sounds as good or better, at a fraction of the price.

peter Moore said...

Hey Rick, On further thought of the $825 HG2. Maybe that has had a face lift in addition to lipstick and powder! $825? That's daft nfor a five watt amp. For that much money you could have a Masco like yours. Don't tell me that doesn't kick a HG2's tweed ass!

Mike said...

The only con with the VHT, which I gigged with with a full band last week without a monitor, is the fake tolex, lol. I somehow too a nice chunk out even though I baby the amp.

An interesting note is that I setup my pedal board through it a few weeks ago. It sounded great, including on alive recording. I took my HG50 out to a gig and realized the effects sound better thought the VHT even with tweaking.

I don't know why, but the delays sound smoother and the filters sit better in the mix.

I had a Kalamazoo and much prefer the VHT, but again, I am totally obsessed with the amp and feel it was totally made for players like myself.

Rick Davis said...

Mike, impressive.

You were right when you told me the little VHT would impress me more every day. It has. Amazing harp tone and build quality for less than $200.

peter Moore said...

Mike, have you done any mods or speaker changes to your VHT?

Don't those VHT's have a copper rectifier?

D.LoSchiavo said...

Thanks for the blog, I've learned a lot from reading.

Just got my VHT--one thing worth noting is that it's truly wonderful guitar amp. I'm going to leave mine stock as I can't find another amp which handles BOTH guitar and harp so well.

Rick Davis said...

D.Lo - Good point. My guitar buddies love this amp, too.