Messages

1

Tape Tech / Re: Stellavox main schematic

« on: June 22, 2009, 11:58:10 AM »

Hi friendly community,

It has taken some time to fix the problem but since yesterday I solved the problem. :-)

At first many thanks to charles who was so kind to send me an image copy of the stellavox schematic. Also I received a part of an schematic view from Mr. Dingler (germany) that both help me to compare and show how the circuit works.

The problem on the Stellavox SP7 was an broken "channel 2" the other channel worked in correct order. Sometimes the channel 2 worked also fine but I realised that the problem occur when the switch "Bass cut-off" was turned to position "S".
In Position "S" the Input/Record amplifier starts to oscillating and the amplifier overdrived.

Now I know the problem was in one of the green axial capacitor (15nF) . The housing of capacitor are plastic and become hardending. In combination on his cable tail in small bending radius the wire got disconnected.

I placed a new capacitor and after this the Stellovox runs perfekt.


Here are some pictures that shows the ugly construction of the stellavox and the broken capacitor at the  switch "Bass cut-off":











Thomas

 
PS: By the way Stellavox has an reincarnation found in this http://www.oravox.ch/frame_en.html

2

Tape Tech / Re: Stellavox main schematic

« on: June 08, 2009, 11:52:28 AM »

Hi Charles,

Many thanks for your help, I have just receive the jpg's from the main schematic of SP7.

I will tell here more then the problem is fixed.

regards

Thomas

3

Tape Tech / Re: Stellavox main schematic

« on: June 08, 2009, 06:40:53 AM »

Hi Charles,

I had send an email on the 5th of june and also days befor as email and PM. Maybe my email is in the spam section of your aol account?

I will resend the email now twice again ( gmx.de and from my work office) .

regards Thomas


PS: My email is : gruenlilie@gmx(dot)net

Please set (dot) = .

4

Tape Tech / Re: 15 isp vs 7.5 isp............

« on: June 07, 2009, 10:45:09 PM »

-On 15ips you will get more dynamic range on higher frequencies.

-On 15ips the recording costs are more.

-On 15ips now LP Tape isn't realy suitable, cause most of them not specified on 15ips

-On 15ips SP Tape (50?m thikness) will be common.

5

Tape Tech / Re: NAB or IEC standard on Revox A77, etc?

« on: June 07, 2009, 11:55:52 AM »

.... I've got a decent amount of NOS Ampex 641 reels and the machine has the bais set for this tape.  However, on the input selector thier is a switch for NAB and IEC; I think I should use NAB since it's supposed to be for a "north america" standard EQ setting? 

......
sincerely,

Donnie L.

Hi Donnie,

On an normal A77 the recordings were made in NAB and you have to play the recordings in the same manner here NAB.

Further more take care about ReVox Tape 641 most of them are for the rubbish bin. They have all the same problem with polyurethan, the emulsion got softens.

An alternative choice for 641 is Quantegy 407 or an RMGI LPR35.

Thomas



 

6

Tape Tech / Re: Stellavox main schematic

« on: June 07, 2009, 08:51:07 AM »

Hi Charles,

if it is to far away to make a scan of the technical documents, please, please make just to pictures with an camera of the main sheet that shows the interconnection of all parts.
I had put an input signal 1kHz to DIN "Diode" input and at the same time I read out the signal from DIN "Diode" output. It shows that signal from CH2 at higher voltage (over -20dB) distorted. This is also without SBO SGC SPA+SOA and SWR, only the modules at the DIN connector were pluged in.

An interchange of SPA+SOA shows no difference, the broken channel is constant channel 2.
I assume that some of the signal capacitors are broken. A view of the interconection schematic would realy help to fix the problem.

Thomas

7

Tape Tech / Re: Stellavox main schematic

« on: June 06, 2009, 02:26:04 AM »

Hi Charles,

thanks for your offer and you will get an email to make me the SP7 documents available.

Thanks in advance and regards

Thomas

PS: Then the failure is fixed I will tell it and pictured it here.

8

Tape Tech / Re: Stellavox main schematic

« on: June 05, 2009, 11:59:42 AM »

Hi Ironbut,

thanks for your friendly words.

I tried in vain twice to contact chris and charles and I didn't get any responce or reaction from both.

Your stellavox link are leading to service in germany and swiss. By phone you won't get contact to Jean-Pierre Gurtner only the answer mashine is running at any time. Maybe the service is abandoned?

Further more I had a contact to Mr. Dingler, he offer a manual plus a schematic sheet for 35Euro plus tax. A lot of money for just some copy of paper.

And if I compare the service manual of an SP8 to an Studer or Revox Service Manual you get from ReVox or Studer much more and better technical documents for less money.

The stellavox is not much common in germany, nagra is much popular.
In germany the stellavox are hardly ever come up for sale, too.
I had an Nagra IV-S and under the aspect of technical construction the Nagra is realy much better than an stellvox.

regards

Thomas

9

Tape Tech / Re: Stellavox main schematic

« on: June 05, 2009, 12:50:09 AM »

Hello all!

Again, what's happend, no answer at all?

If someone has an Service Manual or a part of it that shows the main schematic of an SP7, I can offer an Service Manual in portable document format (pdf) of an SP8.

Please, it would be very kind to make me this document available, cause it is to diffucult to fix the problem on my SP7 without an technical documentation at hand.

Regards

Thomas

10

Tape Tech / Re: Stellavox main schematic

« on: June 04, 2009, 12:48:48 AM »

Hi I'm a new member and my first posting here.

I'm very familiar with reel to reel mashines like ReVox, AKAI, Sony, ASC, Braun and today I have a new one with some trouble.

So I need your help to fix the problem of my Stellvox SP7 with Master 2Track Head-Block.

One of the input channel is broken, but the amplifier modules seams to be in right order.
There are a lot discrete components connect in free style around and on the mainboard, so it is nearly impossible to catch the broken component without an schematic that show what is how connected.

Is here someone who can help with an copy of the main wiring schematic?

Thanks in advance and greeting from germany

Thomas