My first amp (and it works) plus bonus VVR question

[George60]

I just finished my Ceriatone 36W EF86 kit and everything seems to work fine. This is my first amp kit and everything worked with no rework. I was very careful. The amp has a just barely audible hiss (white noise) and I am assumming that is normal.

I have almost no experience with Marshall like amps and I am quite surprised and pleased with the sound. I was afraid that the amp would break up too quick but it has a lot of clean headroom. It will be great for the band I sit in with a good bit. It's a weekend variety band that is known for Linda Ronstadt songs and this amp nails those sounds. Turn the guitar volume down it the amp is even clean enough for Blue Bayou. I am really, really happy with this amp.

Right out of the box the amp has slightly too much bite. I am asumming that it will get mellower with age. The EF86 channel is too bright for me. I have a new Tung-Sol EF806 tube in it.

I have a 2 12" speaker cabinet but no speakers so I am using my Mesa Thiel extension cabinet with an EVM12L speaker. The EV speaker is very close to the sound I am looking for, lots of balls and just a hint of breakup. If they weren't so heavy and expensive I would put EV's in my new cabinet.

My main problem is volume. This amp is too loud for the 'Old Farts' band that I play in. We are all in our 50's, or in my case, 60's and play at low to moderate volume. I would think that the cathode bias Hall VVR would be the ticket. At 36 watts would I need a heat sink for the VVR?

[jeffhorrigan]

If you can bolt the FET to the chassis that is probably sufficient although a heatsink on the top wouldn't hurt as they do seem to generate a lot of heat and getting the heat away from the FET will help its lifepan. The VVR (not from the hall kit) for my 18 watt TMB is bolted to the chassis and I put a CPU style stick on heatsink on the top and have had no problems with it over the past year of use. I also used some heatsink compound between the chassis and the mica/plastic insulator of the FET. I just completed a 5E3 build and installed one of Hall's VVRs but was not able to bolt the FET to the chassis so just used a simple NTE made aluminum heat sink. So far after a month of use I've not had a problem but the area around the VVR get's very hot (61C after about an hour of VVR use.) I used the hole for the standby switch on the 5E3 chassis for the VVR pot and so everything over there gets hot including the nearby chassis bolt. 61C is not a fire hazard but you wouldn't want to put your hand over there for very long. Even without the VVR that side of the chassis gets warm since the transformers, rectifier and power tubes are right below.

[Phil_S]

Congratulations are in order! Fist timer gets it right without rework!

The EF86 input is going to be real crunchy. The pentode input does things tonally that you just don't get with a triode, and I mean in a good sort of way.

I think you are on the right track getting the VVR. That will tame the decibels without neutering the amp. You are already in pretty deep and feeling good about what you can do. Go for it!

Consider buying Merlin Blencowe's book on tube preamps for guitar. There is quite a bit of very accessible information in there. It might help you re-voice the EF86 channel more to your liking. Besides, you may not realize this, but you are now an amp addict and you'll need the book sooner or later.

[1950]

I done a couple of Dana's VVR fittings on a couple of my amps, I can recomend them, chassis mounted vvr on my 18 watter has no probs with heat, chassis always got hot (as they do) before, so no change for mine. I'd like to do seperate pre amp/power amp, vvr 36 watter soon, when I get back on my feet (financially).
Good job on the first time build.

[rjgtr]

+1 on the VVR. It is a simple, but useful design.