TIS 98 (comparison clips added)

[jnewlyn]

I've got my EPos-3 all torn apart and ready to swap out the TIS 58 for the TIS 98. But I need to know the difference between the Base/Emitter/Collector and Drain/Gate/Source. I have the pin out for the TIS 98 but need to know where the legs go. For example, would the 24 VDC be the Collector or Emitter? I'm pretty sure the guitar signal in, is the Base but that's all I know. I'll post the results in this thread once I get this.

Oh, and do I bias this the same way I did the TIS 58?

[jnewlyn]

CRAP. Tried both and this doesn't seem to work. There's no drive or gain going on. The only sound I get is like you'd get if you just barely cracked the volume pot on your guitar. Just a very quiet clean thing. No drive or volume. The other way is about the same except when you hit the strings real hard, you get a more clipped sound and it quickly just mutes out to nothing. Some ting wong. Where's GoodGuest?

[leadguy]

http://forum.metroamp.com/viewtopic.php?f=16&t=25988" onclick="window.open(this.href);return false;

Quotes from sosecho

"The input stage is almost exactly like stage q3 with the exception of the 1K emitter resistor which is instead 3.3K. The collector voltage is 14.3V with 20.8 on the 35uf cap."

"A note of interest might be that this is a echoplex with TIS98 input not TIS58 jfet and it has the compressor board. The compressor board was correctly installed after the record level pot, I don't know if this was done at the factory or by a tech. But the TIS98 input looks original."





So the TIS98 gets hooked up as above but with a 3.3k emitter resistor instead of the 1k emitter resistor up above, and then the output goes to the compressor board.



ie just change the above FET circuit to the above TIS98 circuit and use a 3.3k emitter resistor instead of a 1k emitter resistor.

It's all pretty straight forward I think.

When you had the TIS58 connected to the compressor and then got a lot of noise from the compressor, isn't right somehow.

Compressors are not that noisy.

So I would say there is still something wrong with the compressor part, maybe in power supply.

[jnewlyn]

It is. Already have the 3.3K resistor. In fact, it's a 5K trimmer so I can monkey with it. However, the above is also showing a 470K resistor at the input that bypasses the transistor, to the 22K at the VDC supply. This I don't have and probably need to try. Awesome post leadguy.

[Good Guest]

The collector resistor probably isn't the problem as it works with a wide range of values but follow the pinout correctly with the schematic........

Using a trimpot isn't really necessary the transistor should work flawlessly with the correct values...it's not as finicky as the FET in that regards...22k collector ...etc.


I think a lot of people are looking for too much gain and overdrive with these ep3 preamps.....they weren't designed as boosts and overdrives ..that's just the hypers and bottomfeeders trying to get $$$$ .Tone color, compression , 180 degree phase inversion, and a pre driver for the compressor that's pretty well all one should really expect..if you luck out tho and get a transistor that boosts more than others ..good on ya but doesn't necessarily mean EVH tone.

tis98Pinoutep.jpg (31.21 KiB) Viewed 1572 times

[jnewlyn]

OK, so some progress has been made here. I first had the Collector and Emitter reversed because I didn't realize that the Echoplex schematic was describing the pin out from the "bottom" view. So I got that OK now but the 470K resistor that connects the Base and Collector points, does have to be there or it doesn't work. I also had to dial the 5K trim pot on the emitter side all the way to 0 resistance just to realize a unity gain. It still does cut some just a hair when comparing it in bypass (at which only the MXR 6 band is in front of the amp) I am working with the voltage supply on the other side (25K trim pot instead of 22K resistor) and it seems when I go pretty low (4VDC) I get some gain increase. Not that I'm looking for boost but at the very least, the same as when it's bypassed like I mentioned.

More to come soon.

[Good Guest]

now but the 470K resistor that connects the Base and Collector points, does have to be there or it doesn't work. )

That resistor in this context or circuit can be referred to as the gain resistor ...the higher it goes ..so does the gain..the lower it goes so goes the gain..470k is a good choice.

[jnewlyn]

now but the 470K resistor that connects the Base and Collector points, does have to be there or it doesn't work. )

That resistor in this context or circuit can be referred to as the gain resistor ...the higher it goes ..so does the gain..the lower it goes so goes the gain..470k is a good choice.

You got it. And in doing so, I also tried a 1 meg in there and got just about dead nuts equal drive. Maybe a hair more but nothing of significance in terms of boost. Now that I've got this going, I find myself with a big smile when I play along with VH. Something about it seems to sound even better. I really like it. I don't really know how to explain it but it's just soothing even though it has all sorts of hair and rasp. Like more musical distortion. I think of thin light water boiling vs. a simmering thick soup. Both have heat and steam but the soup has some tasty, tonal flavor with creamy thickness.
OK, kind of a stupid analogy definitely an improvement to my ears. And this is without the compressor. Speaking of compressor. That's next but I'm gonna try and make a clip with just the transistor change for some A/B comparison.

[jnewlyn]

Since I've already done a clip with the TIS 58, I just did a short clip of the everything the exact same except for the transistor change. Both just short and bone dry for comparison. I might be losing it here but these are really really close. I think the TIS 98 sounds a little sweeter though. What do you guys think?

http://www.soundclick.com/bands/default ... ID=1214336" onclick="window.open(this.href);return false;

[rgorke]

James,

Sounds sweeter and smoother to my ears. Nicely done!

Roger

[uiovbged332]

Adidas Yeezy Shoes
Christian Louboutin Shoes
Air Jordan Sneakers
Nike Outlet Online
Nike Yeezy
Nike Sneakers
Nike Black Friday
Red Bottom Shoes For Women
Nike Outlet Store
Pandora Outlet
Nike Air Max 97
Ferragamo
Nike Sneakers Sale
Nike Outlet
Nike KD
Nike Factory Store
Nike Cortez Women
Nike Running Shoes For Women
Nike Shoes
Nike Air Max 270 Men
Lebrons Shoes
Nike Air Max 98
Christian Louboutin Shoes
Nike Clearance Store
Nike Clearance
Adidas NMD
Pandora Rings
Louboutin Shoes
Nike Air Force 1 Men
Jordan 11 Blue
Nike Factory Store
Red Bottom Shoes
Mens Nike Shoes
New Nike Shoes 2019
Christian Louboutin
Louboutin shoes
Yeezy Boost
Nike Factory Outlet
Salvatore Ferragamo Shoes
Nike Shoes
Nike Clearance Store
Air Max 720
Air Force 1 Low
Pandora Necklaces Women
Pandora Jewelry Official Site
Jordan 13 Retro
Vans Shoes Outlet
Nike Air Uptempo
Yeezy 700
Nike Free
New Nike
Nike Running Shoes
Nike Store
Adidas Sneakers
Pandora Bracelet Charms
Adidas Yeezy
Nike Outlet Store
Yeezy 500 Blush
Christian Louboutin
Nike Air Presto
Yeezy 550
Air Max 95
Nike Air Zoom
Nike Basketball Shoes
Nike Sneakers For Women
Pandora Rings
Nike Running Shoes
Nike Shoes For Women
Nike Cortez Men
Nike Outlet Store Online
Air Jordan Shoes
Lebron James Shoes
Pandora Canada
Nike Lebron 17
Nike Factory Outlet
Jordan Kids
Adidas Ultra Boost
Red Bottom Heels
Nike Shoes
Lebron 16
Yeezy Boost 350
Kyrie Irving Shoes
Golden Goose Shoes
Yeezy
Red Bottoms
Nike Air Force One
Nike Lebron 16
Nike Clearance Outlet
Nike Shoes For Men
Moncler Outlet
Jordan Shoes
Cheap Nike Shoes
Pandora Bracelets
Adidas Yeezy
Fjallraven Backpack
Valentino
Nike Zoom
Nike Store Online
Louboutin Outlet
Air Max 98 Gundam
Christian Louboutin
Yeezys
Louboutin Shoes
Pandora Official Website
Jordan Retro 11
Nike Shoes
Kyrie Irving Basketball Shoes
Nike Factory
Air Max 720
Nike Outlet
Nike Store
Pandora
Pandora UK
Nike Outlet
Sneakers Website
Jordan Retro
Asics Shoes Outlet
Stan Smith Adidas
Basketball Shoes
Pandora Canada
Christian Louboutin
Nike Air Force
Adidas Ultra Boost
Pandora Jewelry
Christian Louboutin Outlet
Michael Jordan Shoes
Pandora UK
Retro Jordans
Nike Outlet Store
Adidas NMD
Nike Outlet
Pandora Ring
Ferragamo Belt
Nike Free
New Shoes 2019
Nike Air Max 2019
Air Max
Pandora Jewelry Official Site
Nike Huarache
Fjallraven Kanken Backpack
Louboutin Shoes
Pandora Bracelets