[Harp-L] My New Amp!



Some thoughts-

Different preamp tubes are not likely to make a large difference in the tone

A change in rectifier will affect the power tube bias, but it is not essential to check the bias if the switch is to a lower power recto. In descending order of power, the rectos that will work in that amp are-
5AR4/GZ34
5U4
5V4
5R4
(probably not 5Y3)


A lower power recto will have more sag- sag is the fall in power tube current and plate voltage during periods of high current demand like playing loudly. This makes for a browner sound.

A switch to a lower power recto will result in the tubes being over-biased- that is running at a lower than optimal current. This will not hurt the tubes or amp. You may or may not like the sound of over-biased power tubes- there is more distortion with over bias and some harp amps are intentionally run with this condition. Come to think of it- You may want to intentionally under bias your present tube set up.

Sovtek 5881 tubes are 6L6's. They have a relatively distorted sound.

Mic technique and acoutic volume affect the overdriven sound greatly. Consider working on these.

A tube reverb unit or reverb pedal will soften the attack and delay of a note.

You might consider changes in the resistors in the power supply to drop the preamp tube plate voltages for a dirtier sound. This is a job for an amp tech.

Jim


On Oct 7, 2004, at 5:49 PM, harp-l-request@xxxxxxxxxx wrote:



Message: 13 Date: Thu, 7 Oct 2004 17:44:41 -0400 From: "samblancato" <samblancato@xxxxxxxxxxx> Subject: [Harp-L] My New Amp! To: "Harp-L" <harp-l@xxxxxxxxxx> Message-ID: <MDEFKAOEAIBCJGOIIGKDCEEICBAA.samblancato@xxxxxxxxxxx> Content-Type: text/plain; charset="iso-8859-1"

Hi there folks,

I just bought a new amplifier and I want to pick everybody's brains about
it. This amp is VERY different from my other amp and I can see I'm going to
have to work out some "issues" with it before I play out.


The new amp is a Holland, West Side Andy,2x10, 35 watts. This amp is a far
cry from my Fender Hot Rod Deluxe. My main reason for getting the Holland
is that the Fender just has too many feed-back problems. At home, in my
apartment, it sounds just the way I want it to sound and I'm very happy with
the tone and while a lot of people don't like the drive channel type amps I
actually like the degree of dirt I get from the Fender; it's just not loud
enough to use out in a club. The Holland is a much louder amp.


Here's my issue with the Holland. While it is indeed a lot louder than the
Fender and with way less feed-back, it really has a much cleaner tone. One
of the things I like so much about the Fender is that the added dirt came
with just a littlest bit of sustain and this little bit of sustain tends to
smooth out the edges on my playing. I don't want all you guys to think I'm a
crappy player or what ever; I'm a respectable player. But one thing about
the Holland that I'm finding hard to get used to is this: When I start a
note or phrase and then finish a note or phrase both the start and finish
are rather abrupt. I don't know what you call this quality but I don't like
it. I understand that this has to do with the fact that more power is
getting to the speakers and I also understand that I'm going to have to
tighten up my timing a bit. A buddy of mine who is local has a Holland 4x10
and I've played it a lot with the same problem. I still like the amp a lot
though.


What I want to do is to explore the tonal range of the Holland via the tubes
and see if I can't get a more dirty voice like I like. I have 12AT7s and
12AY7s I can swap around with on the preamp side but this amp also has a
tube rectifier and I know that I can swap Rectifier tubes without rebiasing
the amp. I don't really know anything about tube rectifiers or the kind of
tubes that I can use. The guy who sold me the amp said changing with
rectifier can have a profound impact on the sound of the amp but I don't
know much about this end of the amp other than that tube rectifiers have
something called "sag". I sort of know what this is but not how to
manipulate it. But I do have an idea that this sag is what is causing the
abruptness I described above. Then there are the two power tubes. These
are both Sovtek 5881 tubes. I don't know what this means - I'm used to 6L6
and 6V6 tubes. I do know that you can get different power tubes that have
the same power ratings but sound different- kind of like the Groove tubes
with the red, blue and black color ratings.


So there it is. I would really appreciate any input from whom ever. I know
this is getting pretty esoteric but, hey, this is a pretty esoteric list
after all. I also understand that long discussions about gear can get pretty
boring except for those who are directly involved so if you want to respond
via private email that's cool. samblancato@xxxxxxxxxxx Thanks. Later.







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