Are Audio Manufacturers Liable for False Claims, Bloated Spec's?

[captainbeefheart]

12 hours ago, Westcoastdrums said:

Come on, really?   Really?  Have you heard and bench tested EVERY SINGLE one of his designs. I know you haven't, I'll answer for you.  Don't make a blanket statement like that without doing so n. Be fair. Come on guy... 

 

I have had many acquaintances over the years that love their Carver amplifiers but I will admit I have had the 'pleasure' of making many repairs from friends blowing them up. The problem was instability and not even from ES speakers, many of the Phase Linear amps would go bonkers on even slightly capacitive loads. I will give them credit, Bob was always putting out new service manuals with revisions to part values and such to make the amps more dependable. I have seen many burned spots on his PCB's.

 

I would never go as far as to say Bob is a liar, he was just pushing the envelope of audio technology which comes at a cost of complexity and many revisions to get it correct. I think he has done very well up until this debacle with the Crimson 275 which is just plain sad to see a legend fall so far. Who knows if Bob is even replying, it's probably just Frank that made this mess and Jim has to follow suit to save face and make sales.

[Travis In Austin]

32 minutes ago, captainbeefheart said:

An honest company goes by industry standard specifications. which is your rated output power should be for full bandwidth stated, at maximum distortion stated, and for RMS power into rated load for extended periods of time. So for 75 watts into 8 ohms you should be able to see on a scope a 34.3 volt peak waveform (sine wave) for all interested frequencies and this should not blow fuses. I can purposely clip amplifiers and not even blow fuses for honest amplifiers. You should be able to run a decent amplifier at rated maximum output for long periods. After I do major repairs I run the amplifier at it's full rated output into a dummy load for extended periods of time (hours) to make sure all is well. The Crimson 275 shouldn't be blowing fuses anywhere under 34.3v peak signals, it shouldn't even blow them when clipping either.

Here is what the FTC requires, so I'm wondering if the specs from BCC are in compliance with that (the emphasis, bold and underlining is mine). 

 

§ 432.3 Standard test conditions.

For purposes of performing the tests necessary to make the disclosures required under § 432.2 of this part:

(a) The power line voltage shall be 120 volts AC (230 volts when the equipment is made for foreign sale or use, unless a different nameplate rating is permanently affixed to the product by the manufacturer in which event the latter figure would control), RMS, using a sinusoidal wave containing less than 2 percent total harmonic content. In the case of equipment designed for battery operation only, tests shall be made with the battery power supply for which the particular equipment is designed and such test voltage must be disclosed under the required disclosures of § 432.2 of this part. If capable of both AC and DC battery operation, testing shall be with AC line operation;

(b) The AC power line frequency for domestic equipment shall be 60 Hz and 50 Hz for equipment made for foreign sale or use;

(c) The amplifier shall be preconditioned by simultaneously operating all channels at one-eighth of rated power output for one hour using a sinusoidal wave at a frequency of 1,000 Hz; provided, however, that for amplifiers utilized as a component in a self-powered subwoofer system, the sinusoidal wave used as a preconditioning signal may be any frequency within the amplifier's intended operating bandwidth that will allow the amplifier to be driven to one-eighth of rated power for one hour;

(d) The preconditioning and testing shall be in still air and an ambient temperature of at least 77 °F (25 °C);

(e) Rated power shall be obtainable at all frequencies within the rated power band without exceeding the rated maximum percentage of total harmonic distortion after input signals at said frequencies have been continuously applied at full rated power for not less than five (5) minutes at the amplifier's auxiliary input, or if not provided, at the phono input.

(f) At all times during warm-up and testing, tone loudness-contour and other controls shall be preset for the flattest response.

[39 FR 15387, May 3, 1974, as amended at 65 FR 81240, Dec. 22, 2000]

§ 432.4 Optional disclosures.

Other operating characteristics and technical specifications not required in § 432.2 of this part may be disclosed: Provided:

(a) That any other power output is rated by the manufacturer, is expressed in minimum watts per channel, and such power output representation(s) complies with the provisions of § 432.2 of this part; except that if a peak or other instantaneous power rating, such as music power or peak power, is represented under this section, the maximum percentage of total harmonic distortion (see § 432.2(d) of this part) may be disclosed only at such rated output: And provided further,

(b) That all disclosures or representations made under this section are less conspicuously, and prominently made than the disclosures required in § 432.2 of this part; and

(c) The rating and testing methods or standards used in determining such representations are disclosed, and well known and generally recognized by the industry at the time the representations or disclosures are made, are neither intended nor likely to deceive or confuse the consumers and are not otherwise likely to frustrate the purpose of this part.

[captainbeefheart]

15 minutes ago, Travis In Austin said:

Here is what the FTC requires, so I'm wondering if the specs from BCC are in compliance with that (the emphasis, bold and underlining is mine). 

 

§ 432.3 Standard test conditions.

For purposes of performing the tests necessary to make the disclosures required under § 432.2 of this part:

(a) The power line voltage shall be 120 volts AC (230 volts when the equipment is made for foreign sale or use, unless a different nameplate rating is permanently affixed to the product by the manufacturer in which event the latter figure would control), RMS, using a sinusoidal wave containing less than 2 percent total harmonic content. In the case of equipment designed for battery operation only, tests shall be made with the battery power supply for which the particular equipment is designed and such test voltage must be disclosed under the required disclosures of § 432.2 of this part. If capable of both AC and DC battery operation, testing shall be with AC line operation;

(b) The AC power line frequency for domestic equipment shall be 60 Hz and 50 Hz for equipment made for foreign sale or use;

(c) The amplifier shall be preconditioned by simultaneously operating all channels at one-eighth of rated power output for one hour using a sinusoidal wave at a frequency of 1,000 Hz; provided, however, that for amplifiers utilized as a component in a self-powered subwoofer system, the sinusoidal wave used as a preconditioning signal may be any frequency within the amplifier's intended operating bandwidth that will allow the amplifier to be driven to one-eighth of rated power for one hour;

(d) The preconditioning and testing shall be in still air and an ambient temperature of at least 77 °F (25 °C);

(e) Rated power shall be obtainable at all frequencies within the rated power band without exceeding the rated maximum percentage of total harmonic distortion after input signals at said frequencies have been continuously applied at full rated power for not less than five (5) minutes at the amplifier's auxiliary input, or if not provided, at the phono input.

(f) At all times during warm-up and testing, tone loudness-contour and other controls shall be preset for the flattest response.

[39 FR 15387, May 3, 1974, as amended at 65 FR 81240, Dec. 22, 2000]

§ 432.4 Optional disclosures.

Other operating characteristics and technical specifications not required in § 432.2 of this part may be disclosed: Provided:

(a) That any other power output is rated by the manufacturer, is expressed in minimum watts per channel, and such power output representation(s) complies with the provisions of § 432.2 of this part; except that if a peak or other instantaneous power rating, such as music power or peak power, is represented under this section, the maximum percentage of total harmonic distortion (see § 432.2(d) of this part) may be disclosed only at such rated output: And provided further,

(b) That all disclosures or representations made under this section are less conspicuously, and prominently made than the disclosures required in § 432.2 of this part; and

(c) The rating and testing methods or standards used in determining such representations are disclosed, and well known and generally recognized by the industry at the time the representations or disclosures are made, are neither intended nor likely to deceive or confuse the consumers and are not otherwise likely to frustrate the purpose of this part.

 

"No less than 5 minutes"

 

This is important, and as I said I run the amps at full rated output for at least 5 minutes often much longer to watch for thermal issues.

 

As stated ratings are RMS unless otherwise stated in the specifications. Testing with sine waves at full bandwidth with no more than maximum specified distortion.

 

I personally do not think they have a leg to stand on as their specifications are quite clear, they are deceiving the consumer to think the amplifier can produce 75 watts from 20Hz to 20kHz with no more than 1% THD.

 

Quote from manual:

 

"More than 75 Watts Per Channel, both channels driven at eight
ohms, from 20Hz to 20kHz with no more than 1% total harmonic
distortion. Distortion decreases at lower levels."

 

 

This is deceptive because according to the industry standards of testing the amplifier cannot make the claimed specifications.

[LTusler]

Maybe they just missed the . between the 7 and the 5 in the documentation.

[jjptkd]

Been busy this weekend haven't been able to read through all of the forum updates yet but did want to post Jim Clark's response here from his forum, I plan on sending him an email tomorrow with some thoughts:

 

https://carverstereoforum.com/forums/topic/carverfest-amps-and-how-to-measure-them/#post-3034

 

"You have a satisfaction guarantee for 30 days with a Bob Carver purchase from Jim Clark Stereo in which you can return the 275 for a full refund.. I encourage customers to compare these amplifiers in direct head to head comparisons to any other amplifiers of a similar power rating. I’m not concerned with sine waves and powering load resistors to be perfectly honest. Who listens to sine waves and load resistors? Thats pretty boring and tells you nothing about the amplifiers sound, driving music into speaker loads.

A site with ‘Audio’ in the title seems to ignore this point. Maybe the word Audio, implying sound, should be changed to ‘load resistor’?

I carry products because they are musical and sound great within their price range. I compare several models within a price point and listen to them with different combinations of front ends and speakers.

The units I can offer a satisfaction guarantee with, due to their musical performance are the ones I carry.

The unit has to play well with a variety of other gear and make the customer happiest to win, and not get returned.

The buck stops with the amplifiers performance playing music signals into speakers loads, and the 275 does this better than any I had listened to. Some were over 2x its price.

Customers should continue enjoying the very musical nature of this product, made especially for playing music into loudspeaker loads, and not be concerned with sine wave inputs and driving load resistors.

Use the 275 to play music into loudspeakers and it will make you smile every day without fail… Now if you want to stick your head between load resistors and play sine waves, buy something else."

[Travis In Austin]

4 hours ago, jjptkd said:

Been busy this weekend haven't been able to read through all of the forum updates yet but did want to post Jim Clark's response here from his forum, I plan on sending him an email tomorrow with some thoughts:

 

https://carverstereoforum.com/forums/topic/carverfest-amps-and-how-to-measure-them/#post-3034

 

"You have a satisfaction guarantee for 30 days with a Bob Carver purchase from Jim Clark Stereo in which you can return the 275 for a full refund.. I encourage customers to compare these amplifiers in direct head to head comparisons to any other amplifiers of a similar power rating. I’m not concerned with sine waves and powering load resistors to be perfectly honest. Who listens to sine waves and load resistors? Thats pretty boring and tells you nothing about the amplifiers sound, driving music into speaker loads.

A site with ‘Audio’ in the title seems to ignore this point. Maybe the word Audio, implying sound, should be changed to ‘load resistor’?

I carry products because they are musical and sound great within their price range. I compare several models within a price point and listen to them with different combinations of front ends and speakers.

The units I can offer a satisfaction guarantee with, due to their musical performance are the ones I carry.

The unit has to play well with a variety of other gear and make the customer happiest to win, and not get returned.

The buck stops with the amplifiers performance playing music signals into speakers loads, and the 275 does this better than any I had listened to. Some were over 2x its price.

Customers should continue enjoying the very musical nature of this product, made especially for playing music into loudspeaker loads, and not be concerned with sine wave inputs and driving load resistors.

Use the 275 to play music into loudspeakers and it will make you smile every day without fail… Now if you want to stick your head between load resistors and play sine waves, buy something else."

I agree with Mr. Clark, however he misses the mark here. It's a pivot. Let assume best sounding amp, dollar for dollar. 

 

Does he suggest that potential buyers completely ignore the advertised specifications and just trust their ears? Does he personally market it as a 75W (and more) amp? Does he also extol the excellent distortion ratings that are stated in the specifications. 

 

Every other amp maker who sells in the US rates their amps with sine waves and load resistors what is it about these amps that make it difficult/impossible to be tested in the same way? Lack of grounding? 

 

I don't have very efficient speakers, and past experience has shown that I really need a 75W tube amp for them to sing. Do you recommend this amp if that's the case?

 

And lastly, it looks like the Bob Carver Corporation was dissolved in Washington administratively (they didn't pay their annual fee or file their annual report), and it does not appear that it was subsequently incorporated in Illinois, or California. It they are not around in 2 or 3 years to honor their 5 year guarantee will you honor it Mr. Clark?

 

Or, are you telling me to forget all of that, go with the sound, don't worry about the specs. Trust my ears. There was a guy who had a very similar marketing strategy, expect he put out no specs on his speakers, none. Anwar Bose. 

 

 

 

 

[captainbeefheart]

Specs are there for a reason and should not be fudged for sales with an excuse of 'we don't listen to sine waves on resistors' because that's just plain silly. RMS power is RMS power so list the accurate specifications for your amplifier if you are proud of it's performance and stand behind it knowing "it sounds good".  Plenty of SET amps sound great but they don't advertise them as 75 watts per channel, they are listed honestly as 2 watts per channel and still sell.

 

 

In the blink of an eye Music Direct says the Crimson 275 is no longer available for sale. And this very next thing I noticed is extremely important as an indication of what kind of business Frank is running, every other place that sells the Crimson 275 has added;

 

"SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE"

 

So they are still planning on selling this amplifier with the known bogus specifications but are covering their legal behinds with this very statement upon purchase. How scrupulous can you get? They should immediately CHANGE THE SPECIFICATIONS to exactly how the 275 tests out as and either leave the price and see if they still sell, or lower the price and blow them all out to save a little face in the game.

 

Jim Clark acted like a complete child in the ASR forum. Of course we don't listen to sine waves with resistors Jim, but we do need some standardized method of testing specifications for both the service industry and also for consumers to compare apples to apples before making a purchase. I just cannot believe that was his stance after all this being a dealer, instead he should want to protect his customers and keep his product manufacturers honest.

 

Hate to say it but most of us were not surprised at the test results, the weight of the amplifier was the red flag. What really took me by surprise was how cheap these amplifiers were made with serious safety concerns.

 

Forget the amp not making rated output power. How do people feel about it not even making common safety protocols. If your device has a metal enclosure and is not a Class II double insulated design  it needs to have the outside chassis connected to earth safety ground, no exceptions. To make this very serious matter even worse, they tie the neutral of the mains to the chassis by a resistor. What if your wiring is incorrect in the receptacle? You get a nice warm and fuzzy 120vac eye opener by putting the hot leg on the chassis. This thing is actually scary and I cannot believe it's even in production with all the glaring safety issues. I mean one single point failure could put over 600vdc onto the chassis and there is no protections against that? That's just plain crazy. Add in the glued in current meter and all the other cheapo crap inside and you have a dangerous $500 retail 15 watt per channel tube amplifier selling for almost $3,000.

 

If anyone that purchased this amplifier is seriously considering returning it and is beyond their 30 day money back guarantee I wouldn't ask for a return because of the lower power output, but instead claim it breaks safety standards and is dangerous, make sure you are going to let them know you are writing to the better business bureau and other regulatory agencies over the safety issues concerning the equipment and they might be much quicker to give you your money back going this route.

[jjptkd]

I like this guys take on the situation from the Audiogon forum:

 

grovergardner

5 posts

01-16-2022 7:40pm

I'll suggest some evaluation at this point.  IMO, the amp is cleverly designed to provide 17wpc continuous across the bandwidth at low distortion, with some pretty fair peak power into 8 ohms.  It's a "concept" amp, and as such it succeeds, IMO--a clever design, light weight, large under-biased output tubes that will last for years, current feedback to adjust for low-frequency speaker impedance swings.  Many people say it sounds great--and it probably does in many circumstances.  My old ProAc Response 2's only need 15 wpc to sound really nice in my room.  With the peak reserve, they'd probably be very happy with the Crimson (now Raven, apparently).

The problem is that the amp is sold at 75wpc 20Hz-20kHz at less than 1% distortion.  The amp clearly cannot meet those specs.  Jim Clark claims that only the sound matters--and he's right in some respects, but audiophiles aren't stupid.   Sound matters, but so do honest specs.  So Jim is in a terrible position. 

[captainbeefheart]

45 minutes ago, jjptkd said:

I like this guys take on the situation from the Audiogon forum:

 

grovergardner

5 posts

01-16-2022 7:40pm

I'll suggest some evaluation at this point.  IMO, the amp is cleverly designed to provide 17wpc continuous across the bandwidth at low distortion, with some pretty fair peak power into 8 ohms.  It's a "concept" amp, and as such it succeeds, IMO--a clever design, light weight, large under-biased output tubes that will last for years, current feedback to adjust for low-frequency speaker impedance swings.  Many people say it sounds great--and it probably does in many circumstances.  My old ProAc Response 2's only need 15 wpc to sound really nice in my room.  With the peak reserve, they'd probably be very happy with the Crimson (now Raven, apparently).

The problem is that the amp is sold at 75wpc 20Hz-20kHz at less than 1% distortion.  The amp clearly cannot meet those specs.  Jim Clark claims that only the sound matters--and he's right in some respects, but audiophiles aren't stupid.   Sound matters, but so do honest specs.  So Jim is in a terrible position. 

 

I suppose that is a positive way to view the situation, but more denial than truth. Concept amps are 'innovative' which this amp is nothing of the sort.

 

We have learned things over the years, one things is under bias isn't good, the more current you have the better the performance. Current feedback from the speaker is nothing new and it's not adjustable, I have been telling people the virtues of adjustable positive/negative current feedback from the speaker to adjust damping but this is not the case here. If you look at the frequency plot it is hardly flat, there is a boost in the low end to compensate for poor bass performance in the output transformer. Cleverly named 'DC restorer circuit' is a sliding bias scheme again not new.

 

Now on paper if you were to draw this up you would expect the power output they claim, now that is if you use correctly sized power and output transformers, yes the power transformer is also grossly underrated for this design as well. I really think Bob designed this on paper to be a true 75 watt amplifier except someone in Corporate, most likely Frank Malitz grossly cut corners for profit. Now for people not in the know the transformers are by far the most expensive parts in a tube amplifier, so they skimped out on them to increase profits after they found out during the design stage that it sounds good enough to fool most people for long enough to rake in the dough.

 

Let's put the power issue aside for one moment and I will 100% go with the notion it's a 'concept amp' and people love the sound and that's all that matters.

 

There is one thing nobody should ever cheap out on and that is SAFETY. How do you explain away such gross disregard for safety in this product? Many of you have seen many products with only a two prong bipolar cable but if you look on the back it is Class 2 rated double insulated and sent to UL to be given a third party safety rating. If you do not design the device for double insulation Class 2 and you choose to for Class 1, the metal chassis/enclosure REQUIRES a solid safety earth connection for fault protection. It is there to blow the fuse in situations where something with lethal potentials fails and makes contact to the chassis, without the ground connection the chassis becomes 'hot' and you become burnt toast. The absolute worst part about this is they actually connect the chassis directly to the mains neutral on the primary via a resistor!! 😱 Many old houses and buildings have their Hot and Neutral reversed at the receptacle which is quite scary if you think about it, plug this amp into the wrong outlet and you have a hot 120Vac chassis you can get zapped from. Granted it's a 4.7Meg resistor that will limit current pretty severely but it's still a shock hazard and stupid design that would never meet a third party safety approval. Frank was never going pay for a third party safety approval anyway (big profits remember) so who cares about killing people.

 

Although it's nice to spin the performance of this amplifier as positive there is absolutely zero excuse for blatant disregard to safety.

[jason str]

Lots of excuses and sales fluff, I feel sorry for everybody involved.

 

Never a jeez we made a mistake. Honesty seems rare these days.

[captainbeefheart]

26 minutes ago, jason str said:

Lots of excuses and sales fluff, I feel sorry for everybody involved.

 

Never a jeez we made a mistake. Honesty seems rare these days.

 

So far no official voice from the company has said anything I don't think. Jim Clark was rude complete with name calling about the whole situation and said specifications be damned the amp sounds nice. He claims to only compare sound and price. He completely misses the point of false advertising. So far the damage control has been really poor.

 

I believe the company has already contacted their distributors as they all now say "Specifications subject to change without notice" which tells me they will either update the specifications which I think should certainly be done, or they will just leave that notice up and not change the specs in order to cover them legally.

 

So far Frank and Jim have been nothing but shills on the matter failing to see the problem of grossly bloated specs to make more sales. First they held to their guns and claimed the amps make the rated power, now they have back tracked to specs be damned it's only about how good it sounds. The mental gymnastics are strong with these two, I don't know Jim but many that know Frank dislike him as he is so full of himself and seems to think he knows more than he does which never is a good look for anyone.

[jjptkd]

10 minutes ago, captainbeefheart said:

 

So far no official voice from the company has said anything I don't think.

Yes now that we have an official review of a production amp over at ASR I think we deserve / should expect a rebuttal from Carver or Frank or whomever not just talk but actual proof of claims. Who knows maybe these amps are super-duper special and require some super (secret?) special technique to produce said power output-- seems highly unlikely at this point but hey now is their time to prove all of the naysayers wrong. 

[tigerwoodKhorns]

For anyone interested, here is a great video showing how to size a power transformer.  The math is very simple and he does a great job of explaining. 

 

 

[jjptkd]

From what I've seen online there's near 100 pages across at least 5 forums that I'm aware of concerning this amp, it has been quite interesting to read some of posts describing the workings of the amplifier good and bad although that only probably accounts for a page or two total. 

 

Carver has always been controversial-- he really pissed off a lot of golden ear audiophools with his Carver amp challenge some 40 years ago disproving the myth at the time that you needed top shelf fancy parts to get high end sound, talk about pissing in the cheerios of a lot people! 

 

Personally I think the man is a genius, I have a lot of respect for him and his work and nothing I've read so far has changed my opinion of the sound quality of this amp, I'm sorry it just doesn't. I think moving forward Carver should either update the spec's of the amplifier or provide proof of stated claims but that's just my opinion. 

 

Personally I'm going to be keeping a close eye on the used market-- if these start selling for low prices I'd happily buy a few more. 

[captainbeefheart]

9 minutes ago, jjptkd said:

From what I've seen online there's near 100 pages across at least 5 forums that I'm aware of concerning this amp, it has been quite interesting to read some of posts describing the workings of the amplifier good and bad although that only probably accounts for a page or two total. 

 

Carver has always been controversial-- he really pissed off a lot of golden ear audiophools with his Carver amp challenge some 40 years ago disproving the myth at the time that you needed top shelf fancy parts to get high end sound, talk about pissing in the cheerios of a lot people! 

 

Personally I think the man is a genius, I have a lot of respect for him and his work and nothing I've read so far has changed my opinion of the sound quality of this amp, I'm sorry it just doesn't. I think moving forward Carver should either update the spec's of the amplifier or provide proof of stated claims but that's just my opinion. 

 

Personally I'm going to be keeping a close eye on the used market-- if these start selling for low prices I'd happily buy a few more. 

 

Are you not concerned with safety issues?

[jjptkd]

2 minutes ago, captainbeefheart said:

 

Are you not concerned with safety issues?

This amp has been in production for nearly 4 years probably 100's of units out there maybe more have not seen or heard about any safety issues or failures. 

[captainbeefheart]

26 minutes ago, tigerwoodKhorns said:

For anyone interested, here is a great video showing how to size a power transformer.  The math is very simple and he does a great job of explaining. 

 

 

 

Not a bad video, I have seen a lot worse.

 

He should talk in terms of wattage but that's ok, I know he is specifically talking about the Fender amplifier but the part of the 12A*7 type tubes and the filament needs are incorrect. He says you need 150mA for each triode totaling 300mA per tube, this is correct for 6.3v with them in parallel but these tubes have a center tap and can run on 150mA total for both triodes with 12v across series connection of filaments. Wattage stays the same, no matter the connection each triode requires 945mW of power for a total of 1.89 watts per tube. Trivial in the context of this specific amplifier but I figured I would clarify.

 

The replacement transformer schematic he pulled up that had two primary windings he is wrong about with 120v you only connect to one winding and not both. The paper even says directly on it for 120v connect the two primary windings together in parallel and for 240v connect the two primary windings in series.

 

Third thing I would like to bring up is the fact that with a Class B amplifier like this one you cannot just use power tube idle current as the maximum plate current. That would be correct for a purely Class A amplifier, they are at maximum current during quiescent idle. With a Class B amplifier like this plate current will increase during the Class B portion of operation so drawing loadlines and calculating maximum plate current will give you a better idea of the B+ current rating you will want.

 

[captainbeefheart]

6 minutes ago, jjptkd said:

This amp has been in production for nearly 4 years probably 100's of units out there maybe more have not seen or heard about any safety issues or failures. 

 

But who wants to be the first one to be injured or killed from something deadly like this? We don't know for certain if there has been any issues but assuming nothing can go wrong is not good engineering, you design things for worst case scenario especially where safety is concerned. I don't bend on this, performance is nothing compared to peoples safety.

 

I'm far more concerned with the safety of this amplifier than the performance, if one of these amplifiers crossed my bench I wouldn't let it leave without grounding the chassis and rework the ground network. I have done it a million times with mostly guitar amplifiers but also many Vintage amplifiers that do not meet modern safety standards. I would never want to be responsible for injuring someone or worse, death.