How can a 40 year old amp sound this good?

galyons · « **Reply #20 on:** 12 Feb 2019, 05:57 am »

Quote from: FullRangeMan on 12 Feb 2019, 05:33 am

...
Your statement is the summary of the modern audio dealer trickery and planed obsolescence to sell poor made amps with cheap parts that lasts 5 years for a high price due to their supposed sound quality, while with high quality parts and a simple SE design the equipment would last 20 years or more or as in this topic case 40 years.

...

Ok FRM. If you got that from what I posted, I have no idea how to respond. We are in totally different comprehension universes.

I have built/rebuilt every piece of equipment in my kit from 1960's EV Sentry IVA horns, (rebuilt with custom x-overs), , power amps, preamps, phono stage, tape head, SUT and tubed multibit DAC. My power amps are all SE DHT, (45, 2A3, 300B, SV801-10), that I built, (except for vintage Scott, Heathkit , Fisher and HK, which I restored). So I would obviously speak in "modern audio dealer trickery and planed (sic) obsolescence"

I can imagine my modern audio dealer sales pitch now, "Pssst, do not buy any of this stuff, DIY all the way!"

I do own some modern tube equipment, Rogue 150M Magnums, Rogue 99 preamp, and a bunch of Golden Tube Audio SE40's. Only the SE40's see any service time. (I run the Golden tube Audio Yahoo group.) So I can see we are not on the same page! H@!!, we are not even looking at the same book!

Cheers,
Geary

BobRex · « **Reply #21 on:** 12 Feb 2019, 02:45 pm »

I have an MV75a1 boxed up in my basement. Connected to a PV5, it was my main system for over 10 years. Then I discovered SET and ran a 2A3 amp (Wellborne Moondogs) for another 10 years or so. The MV75 was/is a great amp, esp. for the early '80s. Think about replacing the input connector and possible the power switch. I went through 2 of the push button switches before I replaced them with a paddle switch. Also, check to see if you have an "a" or an "a1". The "a1" mod removed some of the grain and opened up the top end a little bit.

Carl V · « **Reply #22 on:** 12 Feb 2019, 03:17 pm »

LOL
My first good system
Was PV5, MV-50 & Vand. 2Ce then a second MV50.
Then 2w Subs then the MV52 Upgrades.

That PV5 is a nice warm pre-amp with a great PHONO
the MV series Amps were always Pleasant & Tubey...in a good way.
Their Premiere line always had better parts & sounded better, for more money.

cj amps have always been 'musical' not trying to be SS amps in disguise imho

Many of those older designs have a nice sound quality.

mcgsxr · « **Reply #23 on:** 12 Feb 2019, 03:35 pm »

I really enjoyed the Magnavox console pull (sep el84) I used for 10 years. Must have been from the 60’s.

I am currently loving a Sugden Optima 140 integrated from around 1995.

I have tried many kinds of amps over the years and always find that matching speakers and amps is a fun and rewarding pursuit.

Nice CJ!

mick wolfe · « **Reply #24 on:** 12 Feb 2019, 03:37 pm »

Sounds a lot like one of my early systems. PV5/MV50/JSE Model 1's. I believe if I could hop in a time machine, I would find it superb even by today's standards. A few years later I put together a CJ system featuring a PV8/MV75/Spendor 2/3 combo. Very good, but didn't match that first CJ system.

FullRangeMan · « **Reply #25 on:** 12 Feb 2019, 04:04 pm »

Geary, this is a cheap OPT usually found on guitar and hi-fi amps:

Mark Korda · « **Reply #26 on:** 12 Feb 2019, 04:31 pm »

Hi,
there was a guy before the internet came around called Walt Bender. He ran Audiomart which was the primo classified monthly where the search for vintage became a little easier. He said something radical that might help here. It was in Listener Sept./Oct. 2001 in a Peter Breuninger article on the Dyna Stereo 70.
Transformers take 3 to 6 months to come to 80 percent performance but take over 40 years to gain the remaining 20 percent. This explains the stratospheric pricing of old Western Electric gear. It's not because it's collectible, it's for the sound.
True or not, It always makes me wonder. I hope this helps....Mark Korda

Freo-1 · « **Reply #27 on:** 12 Feb 2019, 05:15 pm »

To the OP: Welcome to tube audio.

The are several reasons why the CJ tube amps sounds enjoyable. The major reasons have to do with the differences in transfer function between tube amps and solid state amps. Two significant items are the tube amp's output transformer, and the "soft clipping" characteristics of tubes vs. solid state. As far as tube topology is concerned, SE, P/P, ultralinear, pentode, etc. all can sound good, as long as good engineering principals are followed, and the amp is mated to a set of speakers that work well with the amp (which is the real trick to getting good sound).

I have two sets of DIY tube amps, both which sound excellent. I'm not a big fan of current production tubes, so instead went down the DIY amps road and used good old NOS tubes. The driver tubes for both sets of amps are 6BL7's, which is a very stout tube, well made, and long lasting (they were made for TV sets, which had to be reliable). One set of mono blocks uses a quad of 1625 tubes for the output (which is a 12 volt version of the good old 807 tube made famous in WW2). The amps supply about 110 watts of clean tube goodness. The other mono block amps use a pair of 6883B (which is a 12 volt version of the 6146B). These output around 80 watts of very good sounding power. The tube compliment is reasonably priced, and still obtainable.

Both amps have a Thomas Mayer clone of a 6AH4 preamp that drive the power amps. The 6AH4 preamp is very quiet, and uses transformer coupling to the power amp. The nice thing about DIY is that one can make them with point to point wiring, use better quality parts, and get a great sounding product. Both sets of amps use Mundorf Silver/Gold coupling caps, and those make a huge difference in sound improvement.

Enjoy the CJ amp. Tube audio can be very seductive. Enjoy the ride.

witchdoctor · « **Reply #28 on:** 12 Feb 2019, 06:32 pm »

Quote from: Mark Korda on 12 Feb 2019, 04:31 pm

Hi,
there was a guy before the internet came around called Walt Bender. He ran Audiomart which was the primo classified monthly where the search for vintage became a little easier. He said something radical that might help here. It was in Listener Sept./Oct. 2001 in a Peter Breuninger article on the Dyna Stereo 70.
Transformers take 3 to 6 months to come to 80 percent performance but take over 40 years to gain the remaining 20 percent. This explains the stratospheric pricing of old Western Electric gear. It's not because it's collectible, it's for the sound.
True or not, It always makes me wonder. I hope this helps....Mark Korda

I saw an old Mcintosh amp on Craigslist which I thought would be just a repair job in waiting. Now I may go take a look as I think it is from the seventies so the 40 years has been clocked.

Freo-1 · « **Reply #29 on:** 12 Feb 2019, 06:35 pm »

There is a huge interest in the HK Citation 2 amps. The output transformers are highly sought after.

ketcham · « **Reply #30 on:** 12 Feb 2019, 06:37 pm »

This is an interesting thread. I love my amps now and look forward to many years of enjoyment!!!!!

Goosepond · « **Reply #31 on:** 12 Feb 2019, 06:38 pm »

The older I get, the better I used to be!!!

Gene

timind · « **Reply #32 on:** 12 Feb 2019, 07:32 pm »

A few months ago I bought a Fisher KX 90 (1965) integrated amp. After recapping the power supply, I'm enjoying it quite a bit. I think about swapping in newer coupling caps, but don't want to change the sound of the amp; too sweet as is.

Early B. · « **Reply #33 on:** 12 Feb 2019, 08:05 pm »

Quote from: Goosepond on 12 Feb 2019, 06:38 pm

The older I get, the better I used to be!!!

Hilarious 'cause it's true!!

S Clark · « **Reply #34 on:** 12 Feb 2019, 08:41 pm »

About 15 years ago, Gary Dodd sat in my living room to hook up his prototype battery preamp. At the time I had an old Knight Kit KB85, and he was duly impressed that it didn't have the weak bass he was expecting. 8-10 years later, he used the transformers of that amp to build a custom amp for me that he though was one of the sweetest sounding amps he' ever put together. Old trannies can sound excellent.

Freo-1 · « **Reply #35 on:** 12 Feb 2019, 08:44 pm »

Quote from: timind on 12 Feb 2019, 07:32 pm

A few months ago I bought a Fisher KX 90 (1965) integrated amp. After recapping the power supply, I'm enjoying it quite a bit. I think about swapping in newer coupling caps, but don't want to change the sound of the amp; too sweet as is.

I would not be hesitant to update the coupling caps, as well as power supply parts. I had a Fisher KX-200 some years back, and the refurbishment of coupling caps and power supply diodes made a marked improvement in the sound of the unit. Still had that lush midrange, but it was like a veil had been lifted, and the music came across clearer. Sold it to a good friend who uses it daily.

Found more or less the same results back when I first got into tube gear with refurbishment kits from Vacuum Tube Valley for a pair of Dyna MK IV's and PAS-3.

FullRangeMan · « **Reply #36 on:** 12 Feb 2019, 11:01 pm »

Quote from: S Clark on 12 Feb 2019, 08:41 pm

About 15 years ago, Gary Dodd sat in my living room to hook up his prototype battery preamp. At the time I had an old Knight Kit KB85, and he was duly impressed that it didn't have the weak bass he was expecting. 8-10 years later, he used the transformers of that amp to build a custom amp for me that he though was one of the sweetest sounding amps he' ever put together. Old trannies can sound excellent.

Do it can be the isolation varnish is depleted?

OzarkTom · « **Reply #37 on:** 13 Feb 2019, 12:52 am »

One of the very best preamps I ever heard was the tube McIntosh C-22. It was from the 60's also. These are now selling on Ebay for anywhere form 3-7K. Mac reintroduced that in 2015.

timind · « **Reply #38 on:** 13 Feb 2019, 02:18 am »

Quote from: Freo-1 on 12 Feb 2019, 08:44 pm

I would not be hesitant to update the coupling caps, as well as power supply parts. I had a Fisher KX-200 some years back, and the refurbishment of coupling caps and power supply diodes made a marked improvement in the sound of the unit. Still had that lush midrange, but it was like a veil had been lifted, and the music came across clearer. Sold it to a good friend who uses it daily.

Found more or less the same results back when I first got into tube gear with refurbishment kits from Vacuum Tube Valley for a pair of Dyna MK IV's and PAS-3.

I plan on upgrading the rectifier diodes. Thought about the coupling caps, but the West German "Erofol" caps look cool. I like the flavor of the amp and don't really want to change it. If I want more clarity, I use another amp.

I've changed parts before to get "more" and only ruined the beauty of the original sound.

rollo · « **Reply #39 on:** 13 Feb 2019, 08:45 pm »

Good is as good does. Not much new circuitry these days. CJ is a world class company. They have a house sound which to most ears works very well.

charles