Ceriatone Express Questions-->Suggestions

[Subjecttochange]

I have posted once on this matter and it is still bugging me. No matter what I do to the amp I'm just not feeling it. The harmonic complexity is there. The dynamics are there... but I still feel like something is missing. Maybe it's me, maybe it's the amp...

Does anyone have any experience with the ceriatone's and how they compare to say any one of the fine cloner's amps on this forum? geetarpicker? Dana? Any suggestions of things to do/try?

Everything is stock except for the trannys (Toneslut w/VintageSpec OT) and a VVR.

I have thought about gutting it, thought about giving it a Komet Board, thought about selling it... I don't know. I guess I am just disappointed.

But on the plus side- it launched me into amp building and I'm loving it. Working on a mini plexi now!

[geetarpicker]

Some questions for starters.

What speakers are you using?

Are you able to use the bright switch in the 500pf position?

How far up do you set the gain and controls in general?

What is it that you don't feel is quite right?

Does the amp clean up well?

[Subjecttochange]

A bunch of good questions.

I've got a Celestion V30 and CL80 in a 2x12 closed back cab- not my favorite for starters... but that's all I have.

I do use the bright switch either up or down depending on the guitar. LP stays w/500pF, Strat with the 100pF. Usually...

Generally I use the gain around 12:00 to 1:00. I was playing with it today @ ~2 and things started to get a bit out of hand.

With my Les Paul it cleans up ok. Not great. The strat is better, but that's all the SCs vs HBs.

As far as feeling... I think it just doesn't have power. It's loud. It's quite loud. I think it actually might have too much harmonically going on in the gain texture for my ears (for rhythm), but I think my biggest problem is that it's not very tight. I had a metal panel Marshall and I don't expect it to be that tight. I sold that to get a Trainwreck clone since they seem to have a whole lot more magic. I feel like I have seen a glimpse... but I'm either being cheated- or it's really not the sound for me.

Also Tubes- NOS Sylvania 7025/12AX7(V1&V2), NOS GE 5751(V3), TUNG-SOL EL-34s

LP Standard w/Burstbuckers, Strat Am w/Texas Specials

What do you think? Thanks for your help geetarpicker!

[M Fowler]

Subjecttochange,

Glen K. is the expert on this subject for sure, so I will just add 2 cents worth.

The express gets loud very quick with so much harmonics right out of the chute so back off the volume knob on the amp and on the guitar. Where we are used to having the guitar volume pegged don't do that on this amp.

For more friendly amp you may want to try the 5751 tubes in V1, V2 besides the V3 spot you reported.

wire the NFB to a different impedance load to reduce the NFB to clean up the amp.

I also changed out some of the tone caps to .033 (edited) to get more bass response.

This was to a Ceriatone built Express.

Mark

[Subjecttochange]

Thnaks Mark,

Usually I'll keep my guitar at around 6 most of the time, bring it down to 2 or so for "cleans" and full up for solos.

I do think that most of the time there is too much harmonic distortion too quickly, so I may put in my second 5751 in V1, since I have another good one.

So up the load in the NFB? I'll have to give it a try.

I want to tighten up the bass, do you think that changing the tone caps to .33 will do that? I am assuming that I would want to change the imp. load on the NFB first. What do you think about changing the cathode cap to tighten things up? Lower it to say ~1uF or raising it to say 1000uF?

Also the tone caps are almost all ODs, do either of you have a different preference? I know they can be a bit more harsh...

Anthony

[rooster]

Mark - Woah, are you saying you changed the .022 caps to .33? OR did you mean .033?

And my question to S2C is whether or not you have LOTS of bass or a little bit of bass? Are you saying the amp is getting overwhelmed with bass and that this is part of your problem? Or are you saying that there are other harmonics at play?

Also note to S2C, there seems to be some Express builders here that don't have a lot of bass in their amp. I do not have this problem so I never know if this is part of the complaint scenario. Fill me in then.

[Subjecttochange]

I am assuming it's a plethora of harmonics that are making my ears think it's in the bass range. It doesn't really have an overwhelming amount of bass. Just sort of mushy.

Also- I would guess he means .033.

[mumford]

I don't have anywhere near the expertise of any of these people, but my ceriatone express doesn't have much bass, and is REALLY tight sounding. No mushiness at all--which means I need to practice more.

That said, mine is completely stock from ceriatone parts. It sounds like a really tight Marshall.

[NowFender]

I've been redoing a ceriatone express I bought used and have changed alot of the components (ot,el34 to 6v6,lead dress, 150's to Mallory PVC's,sprague electrolytics,ppimv) but now I'm working on tube choice and speakers. This is the most touch sensitive amp I've owned and it'll also let you know what, if any, pedals it'll work with. Have you tried turning the bass to 9 oclock or so to see if it's not as muddy? I rarely run my bass knob past 12, when I turn up the amp volume I back off the bass (2-12 closed back) or it's way to much, tho this is testing it a home, I'm not that comfortable with it yet to use it out. Also I was using an open back with 1-12 celestion greenback g12H that was a bit to muddy for this amp turned up but nice at low volumes.
IMHO
BTW this was an owner builder not Nik that I got this from.

[Subjecttochange]

Well it may be because its transformers are actually more like a Marshall. I think Nik uses his 50watt irons in the Express w/5200ohm taps (I'm using 6600).

So many variables! I am glad you like it though... I am hoping to get there sometime soon! Keep rocking!
I think we could all practice more- save Glen. He should probably hold off and let the rest of us catch up :D

Got to go for now- a day's worth of classes await. I expect to have this all resolved with perfect solutions upon my return.

Ok just kidding. Thanks so much everyone for the help. Any other suggestions are always appreciated and welcome.
Anthony

[Blind Lemon]

If you want to reduce gain move the 5751 from V3 to V1, if you still want less gain use a 12AT7 in the phase inverter slot, it's better suited than the 5751 unless you want the gain of the 12AX7, which the 5751 is not.

Here's a good read. I didn't write it, so no credit here.................

http://www.guitaramplifierblueprinting. ... verter.pdf


BL

[M Fowler]

0.033 cap

Mark

[Structo]

Yes I read that PI article quite a while back.
But it's a good refresher.

I don't have enough personal experience in rolling tubes in amps to know how much of what he says is in fact true but most of it makes logical sense.

What makes sense is how important the PI tube is to the amplifier since the entire signal has to pass through it.

A kind of choke point if you will.

I don't know enough about tube specs to fully understand but when he says:

Most 12AX7s today show a current output of 0.6-0.8 milliamps where 1.2 milliamps is expected. You throw a 12AX7 in your PI slot with a 0.8mA output and you are 30% down on what the amp can do right off the bat.
........Generally, large plate tubes will show higher standing current but this is not always the case.

Going from a 12AX7 to a 12AT7 in the PI (phase inverter) will yield a change in output tube distortion, touch, and output dynamics in most amps. Is this because the gain is lower in the 12AT7? 10% yes perhaps. The lower gain is a factor but the larger factors are:
• We have almost 10 times the current available to drive the output tubes before the phase inverter starts to break down.
• We have a transconductance of 5500 vs 1600 of the 12AX7. Keeping this simple, it means it takes a lot less input signal for a given output signal.

It seems to make the case that the PI is a very important tone factor in a guitar amp.

Can some of you with more tube experience comment on this article?
What you agree with and I guess almost more importantly, what you disagree with?

[Subjecttochange]

All this to say that the PI is important... if I am understanding the article correctly, it sounds like the 12AT7 is the only way to go? I know some old Hiwatts and Fenders do that. Lower in gain but a higher and more true to expected output current? Right?

This will reduce the gain yes... decrease mushiness? Give me a little more articulation? It said the dynamics will be affected. If so, I do have an extra Amperex 12AT7 that I could use in V3. Don't even know if it works. I just found it laying around the lab.

I'll have to give it a try.

Keep the suggestions Rolling! Thanks guys
Anthony

My lab for Organic Qualitative Analysis awaits!

[M Fowler]

Subjecttochange (STC

Yeah that old 12AT7 you have might be the ticket and many old and current production amps use this tube in the PI position. We will be waiting for your report to see if we can get that amp where you enjoy playing through it. Can you borrow or try your head through a 4x12 cabinet or through some other cabs to see what speakers you like best. Right now I run 212 with C25w/green back and G12H. In the 4x12 I run two english G12V30, 1 new G12v30china, and I carvin vin30.

I stole my 12AT7 from my not use often Fender Super Reverb. No I have to get more tubes to get that old amp back together. I should have put stock in tube production.

Mark