V

viseral audio

Audioholic
just wanted to give a reliable repair shout out Rolland Barr at HI-TECH/carver service for reliable service of my carver TFM75, definitely worth saving.
 
lovinthehd

lovinthehd

Audioholic Jedi
What was the cost? What needed doing? What other brands of amps are they servicing?
 
V

viseral audio

Audioholic
replace right side power supply, recapped most all , replaced one side output board, 1100$ repairs most older amps that can be disassembled from 70,s 80,s 90,s I don't know how bad prices are but understand carver amps to be somewhat complicated, in this day and age I was happy that he was legit and service was performed as promised.
 
lovinthehd

lovinthehd

Audioholic Jedi
Thanks. Wow, $1100 is pretty pricey for repair! Did it even retail for that much new? I have a couple M500t amps I was thinking of bringing them and when I talked to them a few years ago think they were saying $275 per amp. What was the waiting/turnaround time?
 
V

viseral audio

Audioholic
little over 2000$ new bought in mid 90,s, they seemed to be swamped , about little over 4 months, I'm not sure about entire repairs performed its more than I really understand but just got it back yesterday and it sounds better than I remember.
 
V

viseral audio

Audioholic
HI-TECHaudio/carverservice 2241loop rd stevenson, WA. 98648 tel.# 503-618-7605
 
Out-Of-Phase

Out-Of-Phase

Audioholic General
I hate to sound cynical, but is it worth it to repair these older Carver products rather than purchase a new power amp with the latest design topology? There's good value per dollar out there these days.

Or is this a nostalgia thing?
 
slipperybidness

slipperybidness

Audioholic Warlord
I hate to sound cynical, but is it worth it to repair these older Carver products rather than purchase a new power amp with the latest design topology? There's good value per dollar out there these days.

Or is this a nostalgia thing?
Personally, I would say it's only really worth it if I were doing the labor myself.

But, then you are spending the $ on the tools, as the parts tend to be relatively cheap.

Just like working on a car, sometimes it's better to invest in the tools and the knowledge.
 
P

PENG

Audioholic Slumlord
Personally, I would say it's only really worth it if I were doing the labor myself.

But, then you are spending the $ on the tools, as the parts tend to be relatively cheap.

Just like working on a car, sometimes it's better to invest in the tools and the knowledge.
Agreed, at over $100/hour, definitely spend a few bucks on soldering equipment and a multimeter, no need for scopes in most cases.
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
Carver TFM-75 2CH Stereo Amp
Power: 750 watts per channel into 8Ω (stereo)
Frequency response: 20 Hz to 20 kHz
THD: 0.1%
SNR: 100 dB
Damping factor: 200
Gain: 32 dB
Input sensitivity: 1.9 V


Specs remind me of the Pro amps.


$649 Crown XLi 3500 2CH Stereo Amp:
Power: 1,000 watts per channel into 8Ω (stereo)
Frequency Response: 20 Hz - 20 kHz
THD: <0.5%
SNR: 100 dB

Damping Factor: 200
Gain: 36 dB
Input Sensitivity: 0.775 V or 1.4 V



A $300 Yamaha AVR has better THD and SNR:

Frequency Response: 20 Hz - 20 kHz
THD: 0.02%
SNR: 110 dB


https://cdn.soundandvision.com/content/yamaha-rx-v377-av-receiver-test-bench#jA2HpzWUegg8ei1m.99
 
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KEW

KEW

Audioholic Overlord
I hate to sound cynical, but is it worth it to repair these older Carver products rather than purchase a new power amp with the latest design topology? There's good value per dollar out there these days.

Or is this a nostalgia thing?
I associate Carver with the early 80's (and after). Assuming the Carver is (and you would buy) a class A/B amp, is there a "latest design topology" that results in real (audible or significant reliability) improvements?
I think a good amp from the mid-70's is still a fine amp aside from wear and tear (and not having a trigger).
That said, I wouldn't be too quick to put $1100 into it unless I had a lot of history with it and had good confidence in the shop.

But I appreciate you recognize the nostalgia factor
Call me human, but I tend to think of gear I've had for multiple decades as an old acquaintance with fond memories and would rather revive it than toss it on the trash heap!
I know that is nonsense from a strict logic standpoint, but I also know the value of being honest with myself!
Wish I could somehow still have my first car - '65 Dodge Dart ... it was my accomplice in so many adventures!:)
 
Bucknekked

Bucknekked

Audioholic Samurai
Personally, I would say it's only really worth it if I were doing the labor myself.

But, then you are spending the $ on the tools, as the parts tend to be relatively cheap.

Just like working on a car, sometimes it's better to invest in the tools and the knowledge.
I like that answer. Sometimes investing in yourself and tools for your future is better than just a transactional trade.
 
slipperybidness

slipperybidness

Audioholic Warlord
Agreed, at over $100/hour, definitely spend a few bucks on soldering equipment and a multimeter, no need for scopes in most cases.
Scope, function generator, variac, are also wise investments.

If you are patient, you can find excellent deals on the used market.

The nice thing about electronics testing equipment is that the people that own it tend to be the people that take care of the gear and know when it is malfunctioning and how to maintain and repair it. It almost has to be that way by default.

I have an old HP distortion analyzer in my possession right now, borrowed from a friend. It is old, but likely seen little use and in excellent condition. But, it doesn't have a built in function generator and I don't have a high quality oscillator. So, the time that I used it, all I could really measure was the distortion from the function generator as that was orders of magnitude higher than the distortion introduced from the amp.
 
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lovinthehd

lovinthehd

Audioholic Jedi
I hate to sound cynical, but is it worth it to repair these older Carver products rather than purchase a new power amp with the latest design topology? There's good value per dollar out there these days.

Or is this a nostalgia thing?
Just what held me up. Very happy with something like my Crown XLS amps and for the price of repair can get another of those and resale of the M500t is maybe in the $400 area so at least it wouldn't be a loss, but could probably sell them as is and do better.

I associate Carver with the early 80's (and after). Assuming the Carver is (and you would buy) a class A/B amp, is there a "latest design topology" that results in real (audible or significant reliability) improvements?
I think a good amp from the mid-70's is still a fine amp aside from wear and tear (and not having a trigger).
That said, I wouldn't be too quick to put $1100 into it unless I had a lot of history with it and had good confidence in the shop.

But I appreciate you recognize the nostalgia factor
Call me human, but I tend to think of gear I've had for multiple decades as an old acquaintance with fond memories and would rather revive it than toss it on the trash heap!
I know that is nonsense from a strict logic standpoint, but I also know the value of being honest with myself!
Wish I could somehow still have my first car - '65 Dodge Dart ... it was my accomplice in so many adventures!:)
Carver's Magnetic Field tech I believe is called class G.

Hard to say what the value of the TFM 75 is (couldn't find a completed ebay listing but didn't look beyond that), then again look at the crazy prices old Marantz 22/23 series receivers go for....
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
I hate to sound cynical, but is it worth it to repair these older Carver products rather than purchase a new power amp with the latest design topology? There's good value per dollar out there these days.
100% agree. I'm definitely all for buying new amps (or relatively new pre-owned) these days. :D
 
P

PENG

Audioholic Slumlord
Scope, function generator, variac, are also wise investments.

If you are patient, you can find excellent deals on the used market.

The nice thing about electronics testing equipment is that the people that own it tend to be the people that take care of the gear and know when it is malfunctioning and how to maintain and repair it. It almost has to be that way by default.

I have an old HP distortion analyzer in my possession right now, borrowed from a friend. It is old, but likely seen little use and in excellent condition. But, it doesn't have a built in function generator and I don't have a high quality oscillator. So, the time that I used it, all I could really measure was the distortion from the function generator as that was orders of magnitude higher than the distortion introduced from the amp.
It is nice to have those too, especially a variac, though not so much for a function generator. I find for practical purposes, in terms of diy build/repair of amps, software and a mic such as the REW/Umik-1, OmniMic etc., are quite sufficient for many measurements including harmonic distortions.
 
P

PENG

Audioholic Slumlord
Carver's Magnetic Field tech I believe is called class G.
Not really, class G power supply uses multiple rail voltages depending on demand, the Outlaw M2200 monoblock is class G (power supply, amp section itself is class AB). The amp section of the Carver TFM series amps, most likely were class AB as well, but the power supply is of the patented magnetic field type, though it is possible that it also incorporate the multiple rail voltage class G feature, to further improve on efficiency.

Below is a link to the patent.

https://patentimages.storage.googleapis.com/3e/0e/df/3d446d7a3198cd/US4218660.pdf

I read it briefly, my initial impression is that its concept seems quite similar to the switching mode power supply (SMPS). Or the SMPS is a more modern/better form of Bob Carver's magnetic field PS. at least conceptually.
 
lovinthehd

lovinthehd

Audioholic Jedi
Not really, class G power supply uses multiple rail voltages depending on demand, the Outlaw M2200 monoblock is class G (power supply, amp section itself is class AB). The amp section of the Carver TFM series amps, most likely were class AB as well, but the power supply is of the patented magnetic field type, though it is possible that it also incorporate the multiple rail voltage class G feature, to further improve on efficiency.

Below is a link to the patent.

https://patentimages.storage.googleapis.com/3e/0e/df/3d446d7a3198cd/US4218660.pdf

I read it briefly, my initial impression is that its concept seems quite similar to the switching mode power supply (SMPS). Or the SMPS is a more modern/better form of Bob Carver's magnetic field PS. at least conceptually.
Over my head :) I've just seen it compared to class G several times....
 

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