The Doom Room: ILF Edition

[Ancient Astronaught]

What's the THD?

http://www.musiciansfriend.com/amplifiers-effects/thd-bi-valve-30-30w-class-a-tube-amp-head



The BiValve-30 amplifier head from THD is the big brother to THD's popular UniValve model, but with one major difference: dual output tubes. Both the output tubes and preamp tubes give you free reign on endless combinations to experiment with. The BiValve-30 delivers tones from smooth and clear to very aggressive overdrive, like the UniValve, but with more power and a much more compliant output transformer which means richer, thicker lows. It's easily capable of driving a 4x12" cabinet, yet light and easy to handle unlike many other amp heads. It's built-in Hot Plate power attenuator allows for full output distortion at almost any volume, and the unique combination of THD's touch-sensitive input circuit and the wonderfully active and reactive tone control make for a front-end that really responds to subtle and not-so-subtle changes in the signal.

Features
THD BiValve-30 30W Class A Amplifier Head
30W Class A amplifier
Single channel
Hand built
Accepts almost any preamp and power tubes in any combination
Ships with 3 - 12AX7s (preamp) and 2 EL34s (power amp)
More and Less inputs
Volume, Treble, Bass, and Attitude knobs

Retailed around 1800$

[new05002]

i think the amps power is inflated, thats not clean wattage IMO. Generally you going to pull 12-15W for a single 6550 in Class A SE so 2 in parallel about 30W or so. Now if you drive the shit into square waves you will push the wattage up but in a Class A stage you dont have a lot of efficiency. I should say that if your going to get power tube distortion you are going to be fuckin slamming that amp, no ifs ands or buts. Of course an attenuator would help in that case if you wanna achieve reasonable volume out of the cabs. Now, there are schemes to decrease the output power and clip the power tubes but to my knowledge they are not being employed here (voltage regulation via MOSFETs in case your wondering)

Of course, not that 30W is quiet or anything. I have a 5W SE El34 amp and its loud enough to bug people through a 4x12. For skips use in DE, probably more than enough since its not a massive wall of doom fuzz he needs for that band. He has other amps to do that.

lol THD stands for total harmonic distortion, it is a measurement of the all the harmonic content through the audio frequency band. Harmonics are generated through clipping and amplification of the signal. Its more of a hifi term as in guitar amps we have lots of THD all over the place since we are attempting to color the sound a ton. However in the power amp if your looking for the clean power you need to look at the low THD output or its a bit inflated in terms of clean power. Similar to the RMS vs Peak wattage outputs on stuff

[Ancient Astronaught]

i think the amps power is inflated, thats not clean wattage IMO. Generally you going to pull 12-15W for a single 6550 in Class A SE so 2 in parallel about 30W or so. Now if you drive the shit into square waves you will push the wattage up but in a Class A stage you dont have a lot of efficiency. I should say that if your going to get power tube distortion you are going to be fuckin slamming that amp, no ifs ands or buts. Of course an attenuator would help in that case if you wanna achieve reasonable volume out of the cabs.

Of course, not that 30W is quiet or anything. I have a 5W SE El34 amp and its loud enough to bug people through a 4x12.

lol THD stands for total harmonic distortion, it is a measurement of the all the harmonic content through the audio frequency band. Harmonics are generated through clipping and amplification of the signal. Its more of a hifi term as in guitar amps we have lots of THD all over the place since we are attempting to color the sound a ton. However in the power amp if your looking for the clean power you need to look at the low THD output or its a bit inflated in terms of clean power. Similar to the RMS vs Peak wattage outputs on stuff

Ahhhh gotcha, still a slammed 30-45watt amp is much more reasonable on stage then a slammed 200w amp. I'm assuming its more like 30w clean, the owner said it gets more then loud enough to gig with for guitar and even at high volumes has a low noise floor and is very clean.

Well when i was using the 20w jet city verellen in the band before it was loud enough for gigs but the lack of an FX loop bugged me quite a bit. I view this new head as the class A slightly louder version of that head which should be perfect.

Woops... I shouldn't have used THD in two different contexts in that paragraph hahaha Ben said the THD on that amp with ut the boosts on is insanely low, so loud and clean is what its supposed to do until you put the boosts on. There's only one way to find out, and thats when it gets here at hopefully the end of next week.

[new05002]

Nice thing about Class A in general is the lack of crossover distortion. Thats the big bonus there. There is crossover distortion in AB and B amplifiers due to the fact that for a short period of time both halves of the power amp are both off when you switch from one pair on to the other pair on. Now, depending upon how hard you bias the output tubes, the amount of crossover distortion decreases with increasing idle current (or less negative bias)

[AngryGoldfish]

Yeah, I was wondering how the power tubes would clip without increasing the volume like a traditional amp.

I've never heard the acronym THD used before. I know of THD amps—I've always been interested in trying one—but until now I've not heard the phrase 'total harmonic distortion'. I'm going to use it more often to sound sophisticated and knowledgeable.

[new05002]

Read here:

http://en.wikipedia.org/wiki/Total_harmonic_distortion

http://en.wikipedia.org/wiki/Crossover_distortion

[Ancient Astronaught]

For skips use in DE, probably more than enough since its not a massive wall of doom fuzz he needs for that band. He has other amps to do that.

Yes, yes i do.

[whiskey_face]

Agreed, the doom gods must be pleased and sending us spoils of war for our continued efforts.

We're the guy in the middle

Funny you say that, we've been running into all the right gear in some strange ways, It's like the stuff finds us and then things come together in a way were we can suddenly afford it. Burial chamber is a perfect example. When you told me no sweat I can hold it for you, a few things I've had for sale suddenly sold, Destiny... Yeah that might be strong but its really cool how stuff works out sometimes.

and you pmed me about the acoustic
i totally thought a peavey
would have endd up on top of that cab
never dreamed id have an old acoustic
give and ye shall recieve
gear karma in action

I just decided to share the doom gods blessings that were bestowed on me every time I log onto cl or walk into a pawn shop

your welcome guys

[ryan summit]

i think you secretly give guitar lessons
down at he ymca and sals army
fuck i bet you whittle guitars for the homeless
with the luck that you have
can you imagine the stuff youd end up with
if you started givin your stuff away to your bros
wink wink
hey i pmed you about those humbuckers
ill take whatever you think theyre worth
they all boxed up
interesting trades preferred
hows about a folded horn/humbucker even swap
maybe red bear +cash
theyre ultra rare/reliced/removed from butthole
nah hit me big daddy
i wanna get rid of em

[AxAxSxS]

I just decided to share the doom gods blessings that were bestowed on me every time I log onto cl or walk into a pawn shop

your welcome guys

Whatever you're doing, keep doing it. Seems to be working out well across the board lately

[whiskey_face]

:HNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNG:

good deals commith. . . .

holy fuck im shithoused.

work should nver let me out early
cause my machine was DOA today
ryan give me a price baby,
or a trade idea?
bears in the shop atm so its not flyin
what are those hummies out of? guitar wise?
i like replying like you,
slam it it in the ass.
price price babaaaaayh
what are they worth?
pm me :smooches:

[ryan summit]

they came out of a samick
greg bennett tr2
they sound real good
i swapped the neck for the teiscos
then got that gfs loudmouth
switching to private massageee mode


neck. http://www.seymourduncan.com/products/d ... e-2/hb101/
bridge. http://www.seymourduncan.com/products/d ... e-2/hb102/

[CaptainBoxman]

CHECK THY PMS WHISKEY.

[ryan summit]

yes
check thy pms
thanks cap''n

[AxAxSxS]

Made some changes after the show. This will be the backline till the Murrow cab gets done, then the kustom will go. I'll probably keep it but it might be the "bedroom" cab.



New board setup. FUZZY! Thanks again Skip, this rules so hard! It fits right in



So cool



Loving this board now. So much good stuff I can do.