Author Topic: My Stuff  (Read 5758 times)

Online Michon

Re: My Stuff
« Reply #30 on: April 04, 2018, 07:16:57 PM »
Sorry if the above is stating the obvious  but  as a bit of a simpleton I have to describe things on my level.

Thank you for the information in that post Agaton. The "level" was just right. Nothing in the post was obvious to me, as I'm new to tape, and you described it well.

In the case of my Studer A67 I elected to use offboard  tape head amplifier vacuum tube electronics by Bottlehead.

Is it the Eros Tape Head Preamplifier Kit from Bottlehead that you are using with the Studer A67?
https://bottlehead.com/?product=eros-tape-head-preamplifier-kit


Sometimes a switch is used between these but my Tech abhors switches at such low levels( millivolts ,similar to a phono cartridge) and just installed a whole second set of replay electronics for the second replay head .

Did you use another set of Studer A80 Reproducer replay electronics for the 1/4 track playback head, or did you, as with the Studer A67, opt for replay electronics from an alternative manufacturer?
Plate, vakuum buis versterkers en breŽband oorvormers.

Offline Agaton Sax

Re: My Stuff
« Reply #31 on: April 04, 2018, 09:29:29 PM »
Thank you for the information in that post Agaton. The "level" was just right. Nothing in the post was obvious to me, as I'm new to tape, and you described it well.

Is it the Eros Tape Head Preamplifier Kit from Bottlehead that you are using with the Studer A67?
https://bottlehead.com/?product=eros-tape-head-preamplifier-kit


Did you use another set of Studer A80 Reproducer replay electronics for the 1/4 track playback head, or did you, as with the Studer A67, opt for replay electronics from an alternative manufacturer?

Yes an Eros. It was very heavily modified though. Initially it was built with Teflon caps in critical stages and Mundorf gold/silver in oil in others.I think it was also built with special wiring but it is a long time ago and neither myself or my long suffering tech/builder is likely to remember. Later on circuitry was modified : Input valves were changed from EF 86 to EF804 with the circuit adapted. This in the interest of lower noise although the EF804 has a different sound to the EF86 (crisper and cleaner than the warmer but often murky 86/806) . Way back Abbey Road did the same to all their Telefunken eqp. It is said that this change is what gave the Beatles their characteristic sound. True? Dunno. Adjustable pots were also added to the Eros to allow HF linearization.

The Eros was bought as a test bed for the use of outboard electronics. As can be seen it was heavily modified and gain /hum problems was an early frustration only solved by the higher inductance Nortronics heads.

These frustrations led me away from outboard electronics (Cello ,Bottlehead and others  and to the adoption of the superb but rare and earlier Mark Levinson electronics that used the Studer on-board architecture. Both the Levinson and later Cello tape electronics were designed by Tom Colangelo,who took over design after John Curl left the company.

Our very own Valve Audio supremo,Schalk Havenga, once in a moment of sublime insanity, took on  a project to modify a Whisper for tape use. True perfectionist that he is ,this project  quickly became a stunning study in design far removed from the Whisper. Unfortunately for me but fortunately for the world Schalk realised he had a company to run and cannot bankrupt himself  in such silly pursuits and the project was killed off with my blessing. Sadly I lost the design study but it was stunning!

This is the Eros: As can be seen it has had a hard life.

DSCN5785 by jdza, on Flickr

IMG_0525 by jdza, on Flickr

 A80 reproducer:Yes, a second cage was added for the additional replay electronics. Note in the photo neither cages carry any record electronics

DSCN5790 by jdza, on Flickr
« Last Edit: April 04, 2018, 09:53:38 PM by Agaton Sax »

Online Michon

Re: My Stuff
« Reply #32 on: April 19, 2018, 10:39:36 PM »
Adjustable pots were also added to the Eros to allow HF linearization.
What is HF linearization?

Your posts are so informative that I've been scrolling up and down, re-reading several times in order to keep track.

After having bought a few machines recently and researched the topic I am now better able to appreciate how nice the machines in this thread are. As good as it gets in many cases it appears to me.

These frustrations led me away from outboard electronics (Cello ,Bottlehead and others  and to the adoption of the superb but rare and earlier Mark Levinson electronics that used the Studer on-board architecture.
The second photo in your original post shows the ML-5 playback electronics, but Studer branding can be seen on the chassis. Is it that only the chassis is Studer, but the actual electronics are Mark Levinson?

Tape can be of varying width . Most commonly used is a 1/4 inch width though many masters are 1/2 inch. Most "running" masters used for pressing, transfer etc would be 1/4 inch though.  These would be 1/2 track and  run at 15 inches per second. 1/2 track means the entire 6.75 mm (1/4 of an inch)  wide tape would be split in 2,one for the left and one for the right channels. The prerecorded tape one bought in a record store would be 1/4 track at 7.5(or 3 3/4 ) inches per second speed. That means the width of the tape is split in 4 allowing  one to have 1 side of an album on 2 of the tracks, flip the reel over and have the other side on the other 2 tracks.
Do you have a preference with regards to 1/4 inch, 1/2 inch or perhaps even 1 inch?
Assuming the same track count, is it true that 1/2" inch should yield higher fidelity or reproduction quality than 1/4 inch?
Do you have preference between 1/4 track and 1/2 track?
Plate, vakuum buis versterkers en breŽband oorvormers.

Offline Agaton Sax

Re: My Stuff
« Reply #33 on: April 20, 2018, 12:06:49 PM »
What is HF linearization?

Your posts are so informative that I've been scrolling up and down, re-reading several times in order to keep track.

After having bought a few machines recently and researched the topic I am now better able to appreciate how nice the machines in this thread are. As good as it gets in many cases it appears to me.
The second photo in your original post shows the ML-5 playback electronics, but Studer branding can be seen on the chassis. Is it that only the chassis is Studer, but the actual electronics are Mark Levinson?
Do you have a preference with regards to 1/4 inch, 1/2 inch or perhaps even 1 inch?
Assuming the same track count, is it true that 1/2" inch should yield higher fidelity or reproduction quality than 1/4 inch?
Do you have preference between 1/4 track and 1/2 track?

HF. Merely a pot to adjust high frequencies. Most recorders have controls to align for flat replay response. Usually operational at 100Hz and 10 kHz. Used with an alignment tape. The standard Eros has a set output so we added a hf control. So much for those who abhor tone controls.

The Mark Levinson ML5 was a Studer A80RC with audio record and playback electronics by Mark Levinson. There was also an option to have the cables from the heads to audio electronics replaced with silver ML  leads. Heads were specified by ML but  were still standard Studer.

Tapewidth and tracks. In general the more magnetic area available to signal the better the performance. The faster  a tape runs the more area is available for any given signal. Likewise the wider the tape the more area available. So 30 inches per second better than 3 etc. 1/2 track more area than 1/4 etc.