Carver Crimson 275 Measurements

[mhardy6647]

Four KT88's for just 15W?

KT120s.

 

[MakeMineVinyl]

You'd need the audio signal to ride on a high frequency carrier wave of some sort, then the size of the required transformer drops substantially.

The only way I'm aware of involves modulating a high frequency carrier wave.

I don't see enough circuitry in this amp to do that, so what we're left with is a 15 watt amplifier, right?

 

[tmtomh]

I take @Jim Clark 's comments here seriously, and IMHO there's a distinct possibility that these are "amp camp" DIY-assembled units as Jim has hypothesized.

That said, I do think @paulbottlehead should amend the original post (with the help of admins if it can no longer be edited by a regular user) to include a brief note (and maybe a permalink to Jim Clark's first comment in the thread) clarifying that there is some question about the provenance of these units. When the provenance gets sorted out, the OP could again be revised to set the record straight, whatever the outcome.

That would still leave the OP and the entire thread up and open in the meantime, allowing full, open discussion of this matter, while avoiding giving the impression that these are 100% definitely production/warrantied units.

Just my $.02.

 

[TriodeLuvr]

I take @Jim Clark 's comments here seriously, and IMHO there's a distinct possibility that these are "amp camp" DIY-assembled units as Jim has hypothesized.

That said, I do think @paulbottlehead should amend the original post (with the help of admins if it can no longer be edited by a regular user) to include a brief note (and maybe a permalink to Jim Clark's first comment in the thread) clarifying that there is some question about the provenance of these units. When the provenance gets sorted out, the OP could again be revised to set the record straight, whatever the outcome.

That would still leave the OP and the entire thread up and open in the meantime, allowing full, open discussion of this matter, while avoiding giving the impression that these are 100% definitely production/warrantied units.

Just my $.02.

What about the provenance of the dealer unit? Is that in question too? And hasn't Jim Clark confirmed that these 15W transformers are original equipment? If you want the mods to revise the OP's post, please include this info as well.

 

[tmtomh]

What about the provenance of the dealer unit? Is that in question too? And hasn't Jim Clark confirmed that these 15W transformers are original equipment? If you want the mods to revise the OP's post, please include this info as well.

Sure, that would be fine too - I’m not trying to protect Carver here.

 

[Walter]

My first priority is to sort out this warranty issue if there is one. If those amps are in fact production units under warranty (doubtful imho), and the testing was done properly, than those units need factory service ASAP.. A poor performing product under warranty, is not acceptable to Bob Carver, and must be serviced or replaced right away. The OP needs to provide this info.. Lets see the serial numbers. If they were purchased from Jim Clark Stereo, we can track them to the original owner. If they were purchased at another authorized Bob Carver dealer, like Music Direct, I'm still willing to submit the service claim for the owners. This is the quality of service I've come to expect from Bob Carver.. A product in the field not meeting specs, would be totally unacceptable to the factory, quality control, the dealers and especially Bob Carver himself most of all.. Let see the serial numbers and get these amps working properly, assuming the testing of the OP was proper for the design..If they are factory units out of spec, lets take care of the customers first. The OP can retry later.

I can only speak for myself. If I were a dealer who felt that an error had been made, I would do the following:
1. Immediately provide the serial number information required to diffentiate the DIY amps from production versions, instead of just asking the OP to provide the numbers of his with nothing to verify them against.
2.Take the OP up on his offer to buy a production unit with a money-back guarantee, and ship one out FedEx on Monday morning.

 

[SIY]

If anyone in the Northeast has one and wants it measured, my lab is open.

 

[mhardy6647]

If anyone in the Northeast has one and wants it measured, my lab is open.

I'm tempted to buy one & have it shipped to you -- but Mrs. H might keeeeeel me.

 

[mhardy6647]

You'd need the audio signal to ride on a high frequency carrier wave of some sort, then the size of the required transformer drops substantially.

The only way I'm aware of involves modulating a high frequency carrier wave.

It would need to be detected, wouldn't it? Or would this be like the ultrasonic AC bias applied to a tape recording signal to get the record head(s) into a sweet spot for linearity without audible effect (well... except sometimes, when and if the bias signal beats with the 19 kHz FM stereo pilot signal and makes 'birdies')?
PWM sort of works that way, doesn't it? Pracically speaking, that is. I know that long ago folks did at least fiddle with PWM amplifiers using vacuum tubes -- I have no idea how they were coupled to their load (loudspeaker), though. Should the audiophile market be re-investigating vacuum tube PWM amplifiers?

oy, so many questions! I am not part of the solution*. I need more coffee!

______________
* as we like to say in my line of work: If you're not part of the solution, you're part of the precipitate.

 

[TriodeLuvr]

If anyone in the Northeast has one and wants it measured, my lab is open.

I was thinking about making the same offer for anyone in the Austin area. But really, anyone who has one of these only needs to weigh it. If it's 19 lbs., it won't perform as claimed.

 

[amirm]

That said, I do think @paulbottlehead should amend the original post (with the help of admins if it can no longer be edited by a regular user) to include a brief note (and maybe a permalink to Jim Clark's first comment in the thread) clarifying that there is some question about the provenance of these units. When the provenance gets sorted out, the OP could again be revised to set the record straight, whatever the outcome.

A dealer guessing this and that is not data. He hasn't provided any information contrary to OP's measurements. As I noted, if the company has measurements otherwise, let's see it. As is, he is making an argument which fits with thread of discussion that interested parties can read.

I am also happy to put a formal response from Carver in OP's posts if that is provided to me direct.

 

[Jim Clark]

I can only speak for myself. If I were a dealer who felt that an error had been made, I would do the following:
1. Immediately provide the serial number information required to diffentiate the DIY amps from production versions, instead of just asking the OP to provide the numbers of his with nothing to verify them against.
2.Take the OP up on his offer to buy a production unit with a money-back guarantee, and ship one out FedEx on Monday morning.

Agree, If those are Carverfest amps, they will not have any serial number tags. I'm just asking for a picture. All my Bob Carver amps come with a money back guarantee, its been this way for years. Unfortunately they have been out of stock for a couple months now. The factory S/N tags look like this.

 

[Walter]

Agree, If those are Carverfest amps, they will not have any serial number tags.

Ah, OK. If you stated that before, I overlooked it.

 

[paulbottlehead]

I do not see serial tags on either of these, though I need to look at the nicer one to see if there's any adhesive residue where there may have been one.

I also am still waiting for what the differences are between these and production units. We have many examples of kits and manufacturer products coinciding without huge performance differences. Fisher, McIntosh, Dynaco, and Eico all made both kits and factory built examples of various products that perform identically to the factory built units.

 

[paulbottlehead]

In the process of attempting to buy one of these new from a different dealer, I have been advised that these are discontinued and NLA.

 

[SIY]

In the process of attempting to buy one of these new from a different dealer, I have been advised that these are discontinued and NLA.

I can see why.

 

[paulbottlehead]

Thank you for suggesting I check the weight.

 

[paulbottlehead]

Here is 1kHz output with a 4 ohm load at 1% THD.

This is ~6.5W.

 

[tmtomh]

So if these don't have serial numbers, do we feel confident these were not factory-produced models? Or does the possible adhesive area from a possible serial number plate that might have been removed cast doubt?

I understand that even if these were DIY kits that does not necessarily mean these measurements are invalid for the production models. But we here at ASR do value precision of information, yes?

 

[MakeMineVinyl]

So if these don't have serial numbers, do we feel confident these were not factory-produced models? Or does the possible adhesive area from a possible serial number plate that might have been removed cast doubt?

I understand that even if these were DIY kits that does not necessarily mean these measurements are invalid for the production models. But we here at ASR do value precision of information, yes?

One thing seems clear regardless of if they're factory or not; they're using a 15 watt output transformer in a '75 watt' amplifier. Not a good look.