6505 mini head gain and bass issue..?

[whoknows01]

HI all
I have a6505 mini head running it through a laney irt 16 ohm cab first with laney speakers and now loaded with fairly new v30s prob 5 hours on em...
Had the amp maybe for 6 months bought second hand but still as new really ..not much use at all..was baught in usa by previus owner on holiday brought back to australia.. has the built in switching 110 /240 tranny.... i prob have all up 20 hours on head myself ..just bedroom metal type playing...
When i got it, it sounded good through the original laney speakers...expected a little more gain but got there with od pedal in front ...but as of late seems its lost gain ..become fizzy..harsh..thin sounding..very trebbly and bass sounds flubby and muffled like its farting and not much sustain...single notes are very grainy and harsh...and fade really quik... overall volume and clean channel seem ok though
so i changed preamp tubes ..got jjs ecc83s and even ruby ac5hg+ same thing...tsi lights constantly bright green...loaded the v30 to see if speakers were at fault ..
Run a mxr fullbore into effects...seems better still harsh though but thats just the pedal...clean guitar signal into return sound ok..bassy..loud ..warm
also swapped speakers back and fourth ..same prob... oah and adjusted the bias through all levels...diffrent guitars..cables ..etc
anybody have any ideas as to what might be going on..?
had a $50 20 watt ss amp twenty years ago with prob eigh inch speaker and that gain sounded better!!!
any help will be much appreciated...
thankyou all for taking the time to read this..

[Witz32]

This might provide some use. While I don't have a MH, I do have a 3120 and 5150ii. I have two 412 cabs...one is loaded with V30s and the other is an Egnater Armageddon 412. I can't play the 3120 through the V30 loaded cab. The 3120 is much brighter than the 5150ii. The 3120 through the V30 cab sounds way too treblely and as you described, the bass just isn't tight at all. The 5150ii that is voiced differently sounds great through the V30 cab. The 3120 sounds much better through the Egnater cab that has speakers voiced to more bass. Basically I comensate for a dark amp (5150ii) through a brighter cab and my brighter amp (3120) through my darker voiced cab.

I can however get the 3120 to sound pretty good through the V30 cab if I run my MXR M-108 10-band EQ through the FX loop with a Boss DD-3 with just a bit a delay to fatten up the sound. In front I push with a Maxon 808 and an Empress Heavy.

I tried messing and swapping pre amp and power tubes to get the 3120 to sound tight and bassy through the V30 cab...didn't work. Only the EQ and delay in the Fx loop and heavy over-drive in front worked. I can tell you, of the mix above, the one thing that had the greatest positive impact on my tone and tightness was the 10-band EQ. This pedal is uber powerful and very tweakable. Hope this helps.

[whoknows01]

yeah i realise that could have been the case however it started all the mentioned problems before the v30s were used....went back to original laney speakers as a test comparison... its now nothing like it used to sound when i first plugged it into laney speakers..
used to run the bass and presence nearly on full and it sounded thick and tight ..brutal ..now bass over half sound like a mess....i do run a boss eq into effects ..does help but still has lost gain..now sounds so thin. fizzy ..every note is flubby ...chords even sound out of tune , ...you would think its on the clean channell with no crunch and gain on 3/4 while its on lead channell with gain on 7....??

[whoknows01]

Was gonna change power tubes next....
forgot to mention i used to get a quiet heart beat sound thumping through speakers when first turned on for 5 to 10 sec when i first got the amp not always but did happen maybe 5 or so times......still sounded good after however.. now thats been gone for a while..no thumping at all...
And i did see one el84 redplating a couple of times for no more than 10 sec ... when running direct to effect return ...swapped tubes around and it did follow tube..but its never done it again since but that was when i was playing around with the bias ..guitar clean or driven direct into effects return is loud and shows none of the mentioned sound problems..... its gotten to point that i dont even wanna play anymore.!
Anyhow thanks for the help....

[whoknows01]

Anyone else have any ideas...?
Any help will be much appreciated. And thankyou for taking the time to read my long posts ...

[kevin_s]

Mine sounded like you describe then I put in a fresh set of Mesa el84's ans set the bias.
It is now incredible sounding.

[whoknows01]

yeah.. powertubes is my next step...got jjs in it now..
so you think mesa way to go..?
and what about preamp tubes...which recommend.... im after a dark.. pantera type tone if thats possible with that amp
thanks for input..

[kevin_s]

yeah.. powertubes is my next step...got jjs in it now..
so you think mesa way to go..?
and what about preamp tubes...which recommend.... im after a dark.. pantera type tone if thats possible with that amp
thanks for input..

Whatever power tubes you use you will have to set the bias for it to sound right.
I used the mesa el84's because it was convenient for me no other reason.The JJ's are fine.
I still have the JJ preamp tubes in mine in all but one position and that one is a Russian tube but I dont remember the number on it.
If you want to sound like Dime,your going to need more than 20 watts.....LMAO

[whoknows01]

the problems continue....
new power tubes installed ..no improvment..
after some more investigating have found v1 is very microphonic..no matter what tube i use...,volume set fairly high and can hear microphnics through
pressing channel and bright switch..tapping top of amp..tapping around v1 on chassis... tapping top of head...all thumping and tapping through speakers...also get a feedback/cracking sound when placing hand near or holding v1 tube...
other tubes slightly microphonic when tapping.. get a light thump only on high volume ...
that normal for these amps ...??