I have found the holy grail.

Pickups, pedals, amps, cabs, combos

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vojtasTS29
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I have found the holy grail.

Post by vojtasTS29 »

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So i have probably found the best gigging amp ever made.

This thing is absolutely insane. It is a roland solid state preamp into two 7591 tubes(rare af) with a ECC81 phase inverter. Mine had the speaker changed out for a Jensen from a deluxe or something. those very rare 7591s make 30Watts of the sweetest tube saturated sound i have ever heard and once again, along with the super champ tell me, that the power amp is the main thing affecting the sound color.

It also has a super over the top spring reverb, that gives you LSD trips when it is set to 1... 10 is basically noise music levels. It is kind of lightweight, has two channels, an fx loop, somewhat emulated headphone out and a reverb input(no idea about the purpose). And yeah, it is loud. And i am talking insanely bluesbreaker kind of loud. Here in my room, i am having the volume on 1 :D I am in love with that amp.

And guess what. This thing had cost me exactly 5600,- CZK... (220 bucks). I also found out that the 30Watt variant is actually very rare and collectible.
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Bacchus
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Post by Bacchus »

Nice! Kind of weird and cool!

I also think it's funny that the craze about ten years ago was to have a preamp with a tube in it going into a solo state power amp, and this is the opposite of that.
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Post by vojtasTS29 »

I think the craze with the single 12AX7 in everything will never go away. Look at taurus amps. They copied the valvestate technology and advertise those amps as a tube amp... They don't sound too bad, but that is so false advertising i don't even.
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Post by vojtasTS29 »

Schematic. For anybody interested.
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Nick
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Post by Nick »

Bacchus wrote:Nice! Kind of weird and cool!

I also think it's funny that the craze about ten years ago was to have a preamp with a tube in it going into a solo state power amp, and this is the opposite of that.
Musicman amps were also like this (tube power section) and those sound amazing. Will never be the norm because "all tube" is one of those buzzwords that guitarists fall for.
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vojtasTS29
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Post by vojtasTS29 »

Had an eye on the 112RD-65 musicman for a while, too :) But this was way cheaper and i like the sound even more, i don't think i would use its whole 65 Watts, too. I think Around 30-40 is the sweet spot where you can play even over a hard hitting drummer and not destroy your back...
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Gabriel
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Post by Gabriel »

My little 65 Ampeg jet uses 7591S valves and it sounds awesome. Although it only puts out around 12 watts from the two valves.

That sure is an interesting looking amplifier!
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Fakir Mustache
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Post by Fakir Mustache »

Also interesting the phase inverter is valve.
NickD wrote: ↑Fri Mar 25, 2022 11:44 pm
plopswagon wrote: ↑Fri Mar 25, 2022 7:05 pm Fuck! My car runs on Tubes!
When you press the accelerator past halfway it doesn’t actually go any faster, but the engine noise distorts
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vojtasTS29
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Post by vojtasTS29 »

i think that came from the roland philosophy, where they had a lot of sucessful solid-state preamps, but wanted to make the amp valve in the actual amp section.
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NickS
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Post by NickS »

Bloody confusing that the reverb driver op-amp is labelled "1/2 IC2" instead of "1/2 IC1".
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Post by vojtasTS29 »

Ehh. A little update. THe speaker is actually eminence. Assumed Fender special design meant Jensen, but didn't read the word eminence underneath. :D The tubes are held by really cool spring system with a cap on the tubes head, so they won't get damaged or fall out during transport. The reverb is funny. It is not inside a tank, it is just two springs behind the tubes in the chassis, but sounds really nice nonetheless. The phase inverter tube is actually a standard 12AX7, not the AT7, but i bought it from a guy who repaired amps and don't have a manual, so it is probably right.

And now the controls...
Gainy channel has two volumes for two gain stages and a master labeled knob, which is actually just a loudness control of the preamp and does not affect the power stage... Clean channel has just a single volume knob.
Then you get to your standard 3-Band eq and the reverb knob, which, as i said is fucking insanely verby. :D
Then of course your standby, on/off switch and a pilot light.

You have two input jacks, Hi and Low, which to me means no pedals and pedals, i am finding the hi inputs clean tone kind of nicer however.
You have two FTSW jacks, labeled overdrive and reverb... no explanation needed... Next to them is a front panel acessed FX loop, which i find kind of convenient and nice. Thel last jack is the headphone out.

On the back you get an 1 amp fuse screw in slot, two 8 ohm speaker jacks(but i think they are paralleled, so you have to go 2x16 ohms if you want two speakers and a line output.

Lots of things this little combo can do. It really was the rolands answer to the Mark II. :) :D
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Post by 71Smallbox »

How does the dirty channel sound? Roland never seems to get that part right in amps(JC series).
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Post by vojtasTS29 »

Not too bad, but not very dirty at all. Kinda like the blues drive until you crank the amp really hard and then you get power valve saturation.
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Post by NickS »

vojtasTS29 wrote:You have two input jacks, Hi and Low, which to me means no pedals and pedals, i am finding the hi inputs clean tone kind of nicer however.
The Hi input goes straight (well, through 3.3k) to the input transistor with three 1 meg resistors in parallel - input impedance around 330k.

The Low input, when there's nothing in the Hi input, feeds into a divider that drops your input signal to about 1/3rd of its original value and gives an input impedance of around 100K. I would guess that's more for active pickups.

If for some reason you had something plugged into the Hi input at the same time, R101 would be disconnected and the volume/tone could be affected by whatever's connected in its place (like when we couldn't afford an amp each and plugged both guitars into the amp... happy days.

Nerdy stuff:
Overdrive jack/SW1 selects between clean (straight from the input buffer) and the additional gain stage which has the VOL1 control and diode clipping. It also has some roll-off of treble due to C3 and C6. Super nerdy stuff:
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Post by vojtasTS29 »

I am actually glad for people like you who know their stuff :) I would kind of like to know much more about amps at the schematic level. I mean, thats one of the thing that got me into electric guitar.
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