Tate Fosgate 101A connections in system

[63909]

Hi All,
having just got one of these, I've done the 230V conversion and the PSU caps. Everything powers up and there's no evidence of anything amiss at the moment, so I'm at the stage of connecting it up and seeing what the result is. I've downloaded the instruction manual and although its got a few examples of the setups - I can't really see how to integrate it into my system, so I'm after some advice:
I have a Preamp and two matched Stereo power Amps. The manual seems to imply using the tape monitor switches to supply the Tate and the rear amp - then the preamp out to the front amp? The tate has front and back outputs, can these not be connected to the poweramps and the preamp output go to the tate input, or is the tape monitor output used to give a fixed signal so the Tates controls run the volume settings? If anyone has any pointers I'd appreciate it. No great rush as I have to re make the Phono output connection board anyway as there's no chance of fitting any decent RCA's side by side to it - too narrow.
Thanks
Joe

 

[Sonik Wiz]

Hi All,
having just got one of these, I've done the 230V conversion and the PSU caps. Everything powers up and there's no evidence of anything amiss at the moment, so I'm at the stage of connecting it up and seeing what the result is. I've downloaded the instruction manual and although its got a few examples of the setups - I can't really see how to integrate it into my system, so I'm after some advice:
I have a Preamp and two matched Stereo power Amps. The manual seems to imply using the tape monitor switches to supply the Tate and the rear amp - then the preamp out to the front amp? The tate has front and back outputs, can these not be connected to the poweramps and the preamp output go to the tate input, or is the tape monitor output used to give a fixed signal so the Tates controls run the volume settings? If anyone has any pointers I'd appreciate it. No great rush as I have to re make the Phono output connection board anyway as there's no chance of fitting any decent RCA's side by side to it - too narrow.
Thanks
Joe

I don't see any need to be concerned about the tape inputs/outputs.

Just plug your TT, disc spinner, what have you into the appropriate inputs on your preamp. Take the preamp outputs and plug into the Fosgate main inputs. Take the Fosgate decoded outputs & connect to the inputs on your power amps..

Bonus tip: In your member profile there is a spot to list your equipment set up in detail. Strictly optional but it can be a big help for others to check when replying to questions like this.

 

[par4ken]

Hi All,
having just got one of these, I've done the 230V conversion and the PSU caps. Everything powers up and there's no evidence of anything amiss at the moment, so I'm at the stage of connecting it up and seeing what the result is. I've downloaded the instruction manual and although its got a few examples of the setups - I can't really see how to integrate it into my system, so I'm after some advice:
I have a Preamp and two matched Stereo power Amps. The manual seems to imply using the tape monitor switches to supply the Tate and the rear amp - then the preamp out to the front amp? The tate has front and back outputs, can these not be connected to the poweramps and the preamp output go to the tate input, or is the tape monitor output used to give a fixed signal so the Tates controls run the volume settings? If anyone has any pointers I'd appreciate it. No great rush as I have to re make the Phono output connection board anyway as there's no chance of fitting any decent RCA's side by side to it - too narrow.
Thanks
Joe

Yes the most logical (to you and I) hookup is the one not shown. It was assumed that people would use a quad receiver or stereo receiver with a separate rear amplifier. The idea of totally separate preamp and separate power amps is not really addressed. If you are using integrated amplifiers (which include controls such as volume balance and tone controls), then you are all set. The stereo pre-amplifier would connect to the Tate inputs. The tape output will give a steady well balanced level to the Tate. The Tates volume control can be used as a master volume control and you can fiddle with the volume and balance and tone setting of the amplifiers to suit.

If you have power amplifiers (non-integrated) that lack any controls then you are stuck with using the Tate's volume and balance controls only. You will also have no provision for adding discrete sources. The level has to be set by the preamplifier output and the Tate input, it needs a properly adjusted input level. For that reason it is normally best to use the tape output to connect to the Tate. If you instead connect the Tate to the preamplifiers main output you will be able to make use of the units tone controls, but beware that if the channels don't closely track it will degrade decoding.

Myself I use a separate stereo pre-amp and then a home built quad preamp after the decoder incorporating all the controls tone, balance, volume and extra inputs that you would find in a quad receiver. I tend to forget that most people aren't set up that way. My amplifiers are just that; amplifiers pure and simple with no controls, just input and output jacks.

 

[63909]

Hi Par4ken and Sonik wiz,
thanks for your in depth replies. I'll try the tape monitor out into the Tate and then output to the Power amps. I had read that the chips within the Tate are a bit susceptible to over heating, so I thought that I'd ask before connected it. My Pre amp has no tone controls or balance, so using the Tate's and allowing it to set the gain seems safe enough and hopefully will reduce any chance of clipping. I'll get on the rear connections - I don't have any RCA leads that'll fit and see if the unit performs. I update as soon as I can.
Many Thanks
Joe

 

[63909]

I've managed to change the inputs and am working on a permanent workaround for the outputs. As a temporary measure these are mounted on a board outside the unit so I can finally test the unit and see if it works! I didn't have any interconnects that would fit the existing socket spacing
Can I ask: all the sockets as fitted originally are isolated from the main chassis. Indeed I have followed this requirement and my new input sockets are isolated from it too. However, my DMM gives a continuity reading with 10R displayed between chassis and signal ground on all the new sockets and the still original - tape monitoring sockets. There's a 10R resistor on the PCB between both grounds, not being a electronics wiz I take it this 'difference has to be maintained and all replacement sockets have to be isolated from the chassis, can anyone explain why this is done?
Thanks
Joe

 

[par4ken]

my DMM gives a continuity reading with 10R displayed between chassis and signal ground on all the new sockets and the still original - tape monitoring sockets. There's a 10R resistor on the PCB between both grounds, not being a electronics wiz I take it this 'difference has to be maintained and all replacement sockets have to be isolated from the chassis, can anyone explain why this is done?

That would be done to break up any "ground loop" that could cause hum.

 

[63909]

Great thank you.
Had it working for the first time last evening, I'm quite impressed with the outcome. It does show up poor condition disc's though, not that it should surprise me some of these must be 40 years old....
I did have issue with the input balance pot - crystal clear either side of the mid position - but mid position is poor, so balancing the set up is out for now. I gave it a spray of deoxit, but maybe a longer term solution is replacement. Does anyone have any suitable suggestions?
Many Thanks
Joe

 

[Wagonmaster_91]

Great thank you.
Had it working for the first time last evening, I'm quite impressed with the outcome. It does show up poor condition disc's though, not that it should surprise me some of these must be 40 years old....
I did have issue with the input balance pot - crystal clear either side of the mid position - but mid position is poor, so balancing the set up is out for now. I gave it a spray of deoxit, but maybe a longer term solution is replacement. Does anyone have any suitable suggestions?
Many Thanks
Joe

Are you sure that the reason the volume is lower in the mid position isn't because it is canceling out anything that is common (mono) to both rear channels? That is by design. Turning the input balance right or left of mid gives that channel prominence and therefore gets louder because the common items are not being canceled for that channel. (A bit of the Hafler effect.)

 

[par4ken]

IMHO the Achilles' heel of the Tate II are the cheap potentiometers used throughout. I would look on eBay and Aliexpress to find a suitable replacement. You will likely have to buy a lot of five or ten but they are dirt cheap when purchased from China.

Jim used relatively high value pots (200K) to keep input impedance up allowing the use of a low value input coupling capacitors (0.33µFd). Higher value pots and higher impedances in general tend to produce more noise. Oxidation or other contamination will produce more noise than with lower value units. My calculation shows that Jim's choice of values cause bass roll off at 32 Hz with the pot centred. You need to use a linear taper pot for balance and an audio or log taper dual unit for volume. Besides size and lead style the other consideration is to find the right shaft both length and style.

You might want to replace both the input and balance pots with 100K or even 50K units and then also replace the input coupling capacitors with something like 4.7µFd. Wima (Series:MKS2) are available on eBay. Increasing the capacitor size lowers the bass cutoff frequency.

Another suggestion is after treating the pots with DeOxit tip the unit upside down and let it sit that way for awhile so that the liquid will better run down inside the pots.

 

[Sonik Wiz]

IMHO the Achilles' heel of the Tate II are the cheap potentiometers used throughout. I would look on eBay and Aliexpress to find a suitable replacement. You will likely have to buy a lot of five or ten but they are dirt cheap when purchased from China.

Jim used relatively high value pots (200K) to keep input impedance up allowing the use of a low value input coupling capacitors (0.33µFd). Higher value pots and higher impedances in general tend to produce more noise. Oxidation or other contamination will produce more noise than with lower value units. My calculation shows that Jim's choice of values cause bass roll off at 32 Hz with the pot centred. You need to use a linear taper pot for balance and an audio or log taper dual unit for volume. Besides size and lead style the other consideration is to find the right shaft both length and style.

You might want to replace both the input and balance pots with 100K or even 50K units and then also replace the input coupling capacitors with something like 4.7µFd. Wima (Series:MKS2) are available on eBay. Increasing the capacitor size lowers the bass cutoff frequency.

Another suggestion is after treating the pots with DeOxit tip the unit upside down and let it sit that way for awhile so that the liquid will better run down inside the pots.

Quite some years ago my Fosgate 101A started developing noisy front panel pots. Rather than just clean them I thought it was a good time to see if I could replace them with decent sealed cermet pots. I pulled out the input balance pot to make sure of size & shaft length. And then... guess what I never got around to doing?

Agree, the pots were a weak point. But also I was disappointed in the craptastic transformer used and like wise in the Space Matrix line.