Scratch Fairchild 660 Worth it?

[pucho812]

Since I never had the opportunity to do the comparison, I won't argue. I'm just trying to understand the possible objective explanation.

It’s purely a sonic reason here.

 

[abbey road d enfer]

It’s purely a sonic reason here.

I understand that, but there must be a technical reason for it.

 

[pucho812]

I understand that, but there must be a technical reason for it.

well Geoff Emrick would tell me more current to move the music around on a 660 then a 670.

 

[BruceARP]

This is a real good thread. I have built now about 14 670 clones , or at least my version. I do use a solid state side chain amp for several reasons. Many of the reasons are mentioned, lighter weight more headroom , but reliability and stability are the big reasons. While my audio spect meet or exceed the original specs, recently I have built 2 units with switching power supplies and doing extensive testing. Again, much lighter weight, less heat, and the Nigel to noise specs are amazingly good. Much better. Oh and buy the way, I am the only person that has an actual license to use the name Fairchild.
Happy building everyone!

 

[pucho812]

This is a real good thread. I have built now about 14 670 clones , or at least my version. I do use a solid state side chain amp for several reasons. Many of the reasons are mentioned, lighter weight more headroom , but reliability and stability are the big reasons. While my audio spect meet or exceed the original specs, recently I have built 2 units with switching power supplies and doing extensive testing. Again, much lighter weight, less heat, and the Nigel to noise specs are amazingly good. Much better. Oh and buy the way, I am the only person that has an actual license to use the name Fairchild.
Happy building everyone!

By the way, the Fairchild name was purchased and they are making equipment again. So unless that is you, you may rethink that last statement

 

[StarTrucker]

https://www.sweetwater.com/store/detail/670Comp--fairchild-670-2-channel-tube-limiter-compressor

This is the new 670, I believe the name is owned by Telefunken, at least they were cited at the beginning of the reissue process.

 

[Brian Roth]

I'll just sit back with a tub of popcorn and watch as the "I'm Fairchild!" "No, I'm Fairchild!" movie plays out...

Bri

 

[StarTrucker]

Anyone with access to a CNC machine is Fairchild

 

[StarTrucker]

Overall I think they made an intelligent choice, because it doesn't force them as the manufacturer or an end user in need of s retube having to buy so many 6386 - for which JJ has a monopoly and charging a fortune.

Why not substitute for a bunch of 6ba6's with cathode balance pots to set the bias between the two sides. Get them reasonably closely matched and then dial them in by hand. I'm talking about a 660 here

 

[Brian Roth]

Just for grins, I checked the USA Patents and Trademarks website:

https://tsdr.uspto.gov/#caseNumber=...TION&caseType=DEFAULT&searchType=statusSearch

https://tsdr.uspto.gov/#caseNumber=...TION&caseType=DEFAULT&searchType=statusSearch

Both trademarks owned by these folks:

Western Electric Export Corporation (CORPORATION; GEORGIA, USA)

Which are these folks:

https://www.westernelectric.com/

Avid also owns a trademark for "Computer software for audio production."

Those were the only active, audio-related trademarks I found.

Just FWIW!

Bri

 

[pucho812]

Just for grins, I checked the USA Patents and Trademarks website:

https://tsdr.uspto.gov/#caseNumber=...TION&caseType=DEFAULT&searchType=statusSearch

https://tsdr.uspto.gov/#caseNumber=...TION&caseType=DEFAULT&searchType=statusSearch

Both trademarks owned by these folks:

Western Electric Export Corporation (CORPORATION; GEORGIA, USA)

Which are these folks:

https://www.westernelectric.com/

Avid also owns a trademark for "Computer software for audio production."

Those were the only active, audio-related trademarks I found.

Just FWIW!

Bri

that's why I put fare child on my recreations.

 

[beatnik]

Why not substitute for a bunch of 6ba6's with cathode balance pots to set the bias between the two sides. Get them reasonably closely matched and then dial them in by hand. I'm talking about a 660 here

6BA6 types would definitely be the way to go for me, the JJ6386 is just too expensive.
Although now that Stam and Heritage have taken on the 6BA6, they will probably become more scarce / expensive in short time.

I am not sure you need a trimpot for each pair of tubes like on the Stamchild, DaveP has built a 660 with 6BA6 and it seemed to work well with just the stock balancing circuit.

 

[beatnik]

https://www.sweetwater.com/store/detail/670Comp--fairchild-670-2-channel-tube-limiter-compressor

This is the new 670, I believe the name is owned by Telefunken, at least they were cited at the beginning of the reissue process.

35K and they use Alpha potentiometers, or even worse fake Tocos potentiometers, the cheapest rotary switches and tube sockets you can get.

They don't even label the rear panel which even for a small run would cost peanuts.

This has got to be the worst ripoff I have ever seen in the pro audio gear industry.

 

[Rob Flinn]

I am not sure you need a trimpot for each pair of tubes like on the Stamchild, DaveP has built a 660 with 6BA6 and it seemed to work well with just the stock balancing circuit.

I think that just having one trim pot trims all stages, at least to some extent. This obviously depends on the particular stage you are measuring to set the trimmer up.

 

[machprod]

This is the video I was talking about

Sorry, I'm out of sync with the thread, but I love these kinds of videos. If I owned a fairchild I would probably want to do this same test.

WRT that video AND pucho812's statement about 670's. In the video the shifting to the right heard with the poor pairing was also perceptible in the good paring. - I would be very happy with that sound, but my clinical ears do hear the artifact.

I haven't really looked at the RC circuit but it sounds like the right response is slower, or that difference at the mid-point of the compression curve is bigger than the extremities.

 

[StarTrucker]

Which goes against the very essence of a 660. The power amp used to drive the side-chain is a distinctive point.
If you don't do that, you'd better build a 436.

Ok what about a 436 sidechain on a 660 signal amp? Skip the complicated power supply and control amp and just do 8 6BA6s.

It's not a Fairchild so not what I'm looking for, but maybe for someone who wants a 436 without the 436 distortion and a smoother character.

 

[abbey road d enfer]

Ok what about a 436 sidechain on a 660 signal amp? Skip the complicated power supply and control amp and just do 8 6BA6s.

It's not a Fairchild so not what I'm looking for, but maybe for someone who wants a 436 without the 436 distortion and a smoother character.

As long you don't try to pass it for a Fairchild, it's fine by me. You could even replace the 6386's with transistors and use a chip for side-chain, as long as the result suits you, you're free.
My beef is that some people are claiming to make Fairchildren when they change some aspects of the design on the basis that in a real Fairchild it's unnecessary overkill.

 

[CJ]

I was told by Mr. Narma that he did the 660 in his garage, each one took about 3 days to build, and that once he got to Fairchild, Mr. George Alexadrovich was mainly responsible for the 670 design, although I bet there was some collaboration going on there.

That was a tough interview as the night before I drank my usual 8 pack of Guineas draught, a quart of St Pauli Girl, a quart of Steinlager, a shot of Patron and an 1/8 oz of the sticky icky. The phone rings at 8:30 in the morning and some guy with an Estonian accent is talking.
Weaving down the 101 to a hotel in South San Fran with a mouthful of Wrigley's Spearmint but I got er done. Thank God for the hotel bar.

He was impressed with the 3 x 3 foot schematic that Fletcher sent to me for 64 dollars. He flew in to get his daughter situated at Stanford Univ.

 

[HerbertR]

The Poorchild 660 by Analag and Silent Art is one of the best, if not the best, DIY mu-comp project of all time imo. Unfortunately, most 6BZ8/6BC8 tubes have disappeared from the earthball. And besides, many people don't understand linear power supplies and there was a lot of arguing about them. Actually it's a really, really cool compressor. Follows the 670/660 style very closely, without those atomic reactor power supplies and super expensive transformer blocks...... It should be revived
https://groupdiy.com/threads/the-poor-man-660-support-thread.28274/

 

[Rob Flinn]

Ok what about a 436 sidechain on a 660 signal amp? Skip the complicated power supply and control amp and just do 8 6BA6s.

It's not a Fairchild so not what I'm looking for, but maybe for someone who wants a 436 without the 436 distortion and a smoother character.

I made an experimental gain stage with 4x 6BA6 and a pair of edcor transformers. I was controlling the gain with a bench psu. It seemed to work ok. I never got round to trying aproper side chain circuit with it.