Message Board

Doubt it. I have two pairs of active monitors on my desktop, one Yamaha and one KRK. They both run hot. Amplifiers need ventilation.

Jed

As a followup, I ended up getting a board out of an RT-1020L I found on Ebay for $25.00. I changed out one resistor that was different between the two oscillator boards, soldered in the board and viola, erasure has occurred! The deck now sounds great. I still have more adjustments to make but this m...

Think I'm going to break from this for awhile. I replaced all electrolytics and some of the mylar caps. I constantly was checking the ac voltage on the test point as I went. Carefully checking my solder joints, polarities, etc. Still, the circuit was reading low. So I started tapping on the board li...

I pulled out the pot and tested it. Seemed to work fine through it's entire turn. I notice if I apply pressure to the board beneath the transistor that is connected to the pot that the voltage starts to move on the scope. Maybe it's the transistor. All this is also near the oscillator transformer so...

The good news is I replaced 1/2 the electrolytic caps feeding the circuit (will replace the others before I close it up) and the voltage jumped to around 20V. Unfortunately, it will go back down to 8V after a few seconds. When I put the screwdriver into the variable pot and turn it or if I put light...

Yes...the Hakko 808. I'll replace all the electrolytics first and move my way through...I tend to agree with you the more I read and the more I look at the circuit. The deck is Circa 1975 so it's pushing 40. It sounds so good on playback though that I'm itching to get it working.... Thanks man. Inci...

Thanks Scum...as always you are quite helpful. I'll google this wavesolder technique to get an idea of what I'm dealing with. I take it I can't use my Hakko gun to remove the components for this type of work? or can I? I'm going to get out my old notes on transistor circuits and try to understand wh...

I think I am going to start swapping out components on the oscillator board until I find the culprit. The problem is the technology. It looks like they wirewrapped the board to the terminals and I'm worried that the "traces" on the board aren't traces at all. It looks like lumps of solder and I'm no...

Let me ask you guys this, would a low bias voltage make it so the erase head doesn't erase at all? I'm assuming that could be yes since the magnetic field would be weak off the head. The way I envisioned this to work is that both the erase and record head work at the same time. I noticed some gain i...

Here is the oscillator circuit. http://i655.photobucket.com/albums/uu275/Jedanor/Oscillator_zps2d11d7c8.jpg I am getting a very low reading at the test point and VR405 (which the manual says to adjust to get the 22V) is maxed and I'm only reading 8Vpp. Now, I am confused a tad on the schematic. I kn...

Drone wrote:My first question would be, do you have an oscilloscope?

I do.

Jed

I started a thread on another forum regarding this problem. It can be found here. http://www.tapeheads.net/showthread.php?t=24722 The readers digest version is: I think I have a problem with my oscillator circuit and / or my erase head. (The deck doesn't erase at all.) I think I will also need to re...

One thought comes to mind regarding that power supply. The board is fed from it's own external supply. Are you suggesting to install that +/- 15 VDC supply inside the EP3 box and then disconnect the +/- 15 from their transformer and plug to the new supply? If I didn't do it that route, I'd have to d...

I may pick your brain some Jim when I decide to break this board down again. You definitely have me curious. I just gave my Tascam 38 some TLC and will be seeing how it sounds with this board. Hopefully it will convince me even more on analog and refurbing my older gear. I know the music seems to ha...

Thanks for the tip Jim! I'm sure it goes without saying that the board sounded cleaner and he was really happy with it. I'm getting some hum in the Aux's so I need to determine if it is a fault in the circuit or with my ground to the rack. For some reason I thought it was socketed. I'll look again. ...