Ferrograph Series Five inputs.

[Tractorfan]

Hi,
I just tried recording onto my Ferrograph Series Five from my Iphone via two resistors in a 'Y' to combine the stereo Iphone output to mono. I have tried both inputs 1 and 2 and also altering the level on the Iphone and the tape recorder, but the recording is always distorted. Not seriously so, but enough to be annoying and it is more noticeable in the treble than in the bass. It is also noticeable from the speaker when monitoring the recording. The signal level meter is seldom anywhere near the red mark.
Recording onto other machines from the Iphone is OK, and tapes recorded elsewhere play OK on the Ferrograph.
It looks to me as if it's some sort of input impedance mismatch. Do Ferrographs have an odd input characteristic compared to other run of the mill tape recorder?
Cheers, Pete.

[TIMTAPE]

It wont be an impedance issue as both Ferro inputs are pretty high impedance.
The right hand input would probably be better. The left might be too sensitive.

When using the right hand input I think you were supposed to insert a shorting plug into the left hand input although with a low impedance output from your Iphone it shouldnt be necessary. What value resistors are you using?

Performance on 3 3/4 ips was always pretty terrible on my Series 5. The treble used to saturate fairly easily. 7 1/2 ips was much cleaner sounding.

[SteveCG]

Pete,

A couple of thoughts for you:

1) Are you using a tape type appropriate for the Ferrograph? ie an old non-low-noise era sort. Faint over-bright recordings can be caused by under-bias, which is a condition you would get using a modern (but shiny-backed) tape on a machine which was still set-up for its orginal tape type.

2) Have you changed any of the paper capacitors in the machine? I found that those in a Ferrograph 2 I once dealt with were all electrically leaky.

By the way, as Timtape says, in using the right hand input Ferrograph recommended a shorting plug be inserted into the left hand input (certainly for the Ferrograph 2).

[Tractorfan]

Hi, And thanks for your replies.
I have no idea what tape I'm using, I use whatever I have handy as long as it's not actually degrading or suffering sticky shed. Tapes recorded on other machines sound OK on the Ferro. Having said that, The distortion is audible through the speaker even with the tape stationary, so it's something to do with the inputs rather than the tape itself.
The caps in the Ferro are either those mustard coloured ones, or silvery Suflex ones which, I understand, are usually OK. I changed only two of Hunt's electrolytics that I could find and it works well for its age.
I'll certainly try the shorted jack plug trick though.
Cheers, Pete.

[SteveCG]

Pete,

Since you get distortion via the monitor speaker only in record mode then about the only other thing I can suggest is to check the resistor values in the record/replay circuit - if you are sure the coupling capacitors are indeed alright.

BTW is the HT voltage correct?

[Tractorfan]

Hi Steve,
Thanks for your thoiughts on my Ferro. I'll open it up again and have a good poke around with the meter prods. Meanwhile, I have a Tandberg that's suddenly developed a naughty problem, so that's now in bits on the bench awaiting a quiet afternoon!
It never rains, but it pours!
Cheers, Pete.

[peter_sol]

I would think that your input is too high try wiring a volume control just before the input socket. Does a tape play OK?

[SteveCG]

I don't have a circuit diagram for a Series 5, but I thought that the right-hand input was wired across the input to the level control, so provided your actual input signal is not distorted in the first place, you would be looking downstream of it for the reason for the distortion. Have you got a circuit diagram?

You did say that the meter deflection was well below the redline, but the monitored sound was distorted; that to me is a puzzle since a lot of the replay circuit is common to the recording circuit, yet you find that the tape-recorder can replay tapes without distortion.