sonic I

[Duffy]

I just got a sunn sonic I, I need some info on it. sunn logo kinda pinkish with no pat indacator. numbers for controls are on the chassis face and not on the knobs could be 66 or67? It came with 6l6 pwr tubes, sounds weak and I am to understand this amp needs kt88's before I do that I need some input on this amp. also has the 7199 in the cicuit, Thanxs

[loudthud]

If the 7199 is original, the amp should have EL34s. Check the 12AX7. It's around front by the input jacks between the output transformer and the grill cloth panel. Someone may have subed a 12AT7 or 12AU7 in there.

[Duffy]

If the 7199 is original, the amp should have EL34s. Check the 12AX7. It's around front by the input jacks between the output transformer and the grill cloth panel. Someone may have subed a 12AT7 or 12AU7 in there.

Hi, it does have the 7199 and the pre tube is a 12ax7. so the 6l6s are incorrect? and the kt88s wont work? Then I will obtain correct tubes el34s for it also in looking at the site I realized it has a two prong cord and a polarity swtch. any advice

[biltmore]

Yeah, it should definitely have EL34's in it (It's a 40 watt amp). Those 6L6's have to go! The Sonic II is the one with KT88's in it.

I was looking into buying a Sonic I a while back, but it wasn't in the greatest condition and wasn't working at the time. I always wondered how those lower wattage Sunns sounded like.

[Duffy]

Yeah, it should definitely have EL34's in it (It's a 40 watt amp). Those 6L6's have to go! The Sonic II is the one with KT88's in it.

I was looking into buying a Sonic I a while back, but it wasn't in the greatest condition and wasn't working at the time. I always wondered how those lower wattage Sunns sounded like.

Well thanx for the info, el34 by jj on the way and the 3 prong cord is in and the polarity and death cap are out, telefunken ax7and jan 7199 in front now and Ill let you know how it sounds

[Soundmasterg]

Yeah, it should definitely have EL34's in it (It's a 40 watt amp). Those 6L6's have to go! The Sonic II is the one with KT88's in it.

I was looking into buying a Sonic I a while back, but it wasn't in the greatest condition and wasn't working at the time. I always wondered how those lower wattage Sunns sounded like.

The later amps with the Schumacher transformers shared the Sonic 1 name but used 6550/KT88's and the 6AN8 phase inverter. I have one from 1970 that is this way. It was originally a Sonic 1, from the factory with the larger transformers intended for the 60 watt amps. The faceplate had everything sun bleached on it when I got it, so I relabelled it into a 200S because its the same amp and that was easier to do too. But anyway, not all Sonic 1's used the smaller transformers and EL34's. Sounds like this guy's did though.

Greg

P.S. A friend of mine locally has a very early Sunn with the smiley face logo and EL34's and it sounds great. It overdrives and crunches up a little earlier than the KT88 amps, but is very warm and balanced sounding.

[Duffy]

Yeah, it should definitely have EL34's in it (It's a 40 watt amp). Those 6L6's have to go! The Sonic II is the one with KT88's in it.

I was looking into buying a Sonic I a while back, but it wasn't in the greatest condition and wasn't working at the time. I always wondered how those lower wattage Sunns sounded like.

The later amps with the Schumacher transformers shared the Sonic 1 name but used 6550/KT88's and the 6AN8 phase inverter. I have one from 1970 that is this way. It was originally a Sonic 1, from the factory with the larger transformers intended for the 60 watt amps. The faceplate had everything sun bleached on it when I got it, so I relabelled it into a 200S because its the same amp and that was easier to do too. But anyway, not all Sonic 1's used the smaller transformers and EL34's. Sounds like this guy's did though.

Greg

P.S. A friend of mine locally has a very early Sunn with the smiley face logo and EL34's and it sounds great. It overdrives and crunches up a little earlier than the KT88 amps, but is very warm and balanced sounding.

You guys have been a great as I have now learned that it has the dynaco transformers in it,so early model with 7199 and el34s,thanx

[biltmore]

Ahhh, I was under the assumption that all Sonic I's were 40 watt models. Thanks G!

[Soundmasterg]

Ahhh, I was under the assumption that all Sonic I's were 40 watt models. Thanks G!

Yah I used to be too until I got this one several years back. I think you could safely say all the Dynaco transformer Sonic 1's are the 40 watt model though.

The Dynaco transformer amps sound better overall anyway to my ears. A little less volume due to the lower voltages, and they sound sweeter as a result. The highs aren't quite so over the top....but that said, the later ones still sound good.....just not as good as the earlier ones. YMMV of course. The 60 watt Dynaco amps are more like 530v instead of the 560v on the plates of the Schumacher amps.

Greg

[HRobert]

Ahhh, I was under the assumption that all Sonic I's were 40 watt models. Thanks G!

Only the earlier ones.  In high school I worked with a bass player that had a "67" Sonic I that he used for bass.  It had a JBL D-140, but wasn't labled "SONIC I-40'  like the later models. It also had the numbers on the faceplate and the pointer knob...where as my Sentura II had the numbered knobs.  Anyway, the 40 watt Sonics sounded great.

[Soundmasterg]

The Sonic I-40 isn't the same as the Sonic 1. They are both individual models in the Sunn amp line, and the earlier Sonic 1's are 40 watts while the later ones are 60 watts with the associated changes in tubes and transformers between them.

Greg

[Duffy]

For your info. I have finished the sunn sonic 1 upgrades. from stock: a three wire plug adding a solid ground.polarity switch removed from circuit. jjecc803 gold pin, jan 7199 and jjkt 77 replacing el34 tubes as this is used for lower volume bass gigs.enough level on the bias pot to bring the tubes into good operating range.I chose not to do the 6u8 from 7199 mod at this time and when the 7199 in it is done I will as the 7199 is at 50 dollars today and the jan 6u8 was 9 bucks and is standing by.rich, warm tube tone and good volume capable. Sweet! Is there a direct replacement for the large can cap?works and is the origanal, I would like to get a new one. and anyone know if there are murcury trannys for this or am I better to keep the dynacos that are in it?Thanks this site has helped a lot, Danny

[doomedfuzz]

For your info. I have finished the sunn sonic 1 upgrades. from stock: a three wire plug adding a solid ground.polarity switch removed from circuit. jjecc803 gold pin, jan 7199 and jjkt 77 replacing el34 tubes as this is used for lower volume bass gigs.enough level on the bias pot to bring the tubes into good operating range.I chose not to do the 6u8 from 7199 mod at this time and when the 7199 in it is done I will as the 7199 is at 50 dollars today and the jan 6u8 was 9 bucks and is standing by.rich, warm tube tone and good volume capable. Sweet! Is there a direct replacement for the large can cap?works and is the origanal, I would like to get a new one. and anyone know if there are murcury trannys for this or am I better to keep the dynacos that are in it?Thanks this site has helped a lot, Danny

I'm sorry my friend, I am enjoying reading your posts and this thread in general, and I hate to be the forum police as I hate when people are, but please a space after a period - just super hard to read. Thanks...

[Duffy]

Thanks for the info, I will