PARKyfing a plexi 50 Watt

franc · Post by **franc** » Sat Feb 03, 2007 2:29 am

This thread (http://forum.metroamp.com/viewtopic.php?t=9511) got my blood boiling for an orange Park-like amp.

I don't care whether there exists an orang Park 50 or not, I just think it looks
cool

So I'm having black plexi fronts made, a black logo and I am building an orange smallbox

I'm kind of mixing the Marshall and Park look, because I'm not splitting up the 2 channel volumes and inputs and my box will be a regular smallbox size, but with the not-rounded front cutout and no goldstring across the front.

After deciding I wanted to do this, I found out that actually, I should build a Park 75 with KT88 tubes!!

So my question is: in what way would I need to change my plexi 50Watt clone to accomodate these tubes? I know I will probably have to lower the bias resistor from 220k to 150k or so, but will the OT survive 2 KT88s?

What B+ do I need?

I have no idea what it will sound like, but I am positive it will be a looker with the big KT88s (I probably wont put on a backpanel), orange box and black plexi

franc · Post by **franc** » Sun Feb 04, 2007 11:11 am

35 Views and no-one has any ideas?

MacGaden · Post by **MacGaden** » Sun Feb 04, 2007 3:30 pm

Hi Franc:

I have a

sweetwilliam · Post by **sweetwilliam** » Mon Feb 05, 2007 4:49 pm

So a 50 watt OT and PT will handle the KT88's? Just asking cause I have been kicking around the idea of building a 1/2 power Major but wasn't sure what trannies to use.

NOW IT'S ON!!!!

OnTheFritz · Post by **OnTheFritz** » Mon Feb 05, 2007 5:43 pm

I thought the Park 75's used KT-77's?

Same tranny's for sure though.

Guitar Adjuster · Post by **Guitar Adjuster** » Mon Feb 05, 2007 6:58 pm

I built a 50watter using one of George's Heyboer 50 PT and OT then changed it to a 2204 w/6550's and had no problem at all. I think the PT could handle KT88's just as good as 6550's.

franc · Post by **franc** » Tue Feb 06, 2007 8:28 am

Thanks for your input guys.

The PT might put out too low a voltage, but if I'd use a JTM45 PT I might just have enough (350V)

So would you guys suggest JJs, EHs or what type of KT88s?

sweetwilliam · Post by **sweetwilliam** » Tue Feb 06, 2007 4:23 pm

When I first got my '78 2204 it had 6550's. I changed over to EL 34's and didn't notice much of a difference in volume. Do the KT88's operate at a higher voltage than 6550's, or do the 2204's not give all the juice the 6550 can handle?