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Post by myles on Jan 31, 2007 20:10:34 GMT -7
Just a bit of a heads up ... Many of you know that Carl Verheyen ( www.carlverheyen.com ) put his vintage Marshalls to bed and switched to the SRZ-65. Carl will be receiving his second SRZ-65 in a few days. At that time we are going to be doing a bit of a project since we will have two of the same amps (although one is Europe voltage and will use a step up transformer for the testing here in the USA). First, all the preamp tubes in both amps will be the same and be trace matched to each other to eliminate that from impacting the results. What is going to be attempted is to see how far we can go with the amp using some simple non-mod changes. Sometimes Carl likes more clean headroom .... so a 12AT7 will be tried in V3 ala Fender amps. A 12AY7 and 5751 will be tried in V1 and then in V2 and then in V1 & V2 in various combinations. A duet of EL34M's will be tried and biased experimented with a bit. The JJ KT-77 will be tried in a #8 rating and biased at 60%+ ID. These are very bold tubes and I have had some cool results with them in other amps. Lastly, a solid state rectifier will be tried. I already warned Carl that the magic touch dynamics of the amp will be reduced and he does not want to loose that aspect of the amp but we are going to see what happens. When this is done the B+ voltage change before and after SS rectification will be reported as will the power output before the onset of clipping (clean output) and the flat out wattage of the amp. So ... this is just a bit of a heads up. Maybe I can get Carl to write up his take on things from a player's point of view rather than my tweekers point of view
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Post by Phil (aka Phil) on Feb 1, 2007 5:13:22 GMT -7
Myles, Does Carl own the black cab/red front SRZ that he is pictured in the GT ads with? I somehow got the idea that he was borrowing yours. Did the Doc build him one just like yours ?
PDW
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Post by myles on Feb 1, 2007 9:54:00 GMT -7
Myles, Does Carl own the black cab/red front SRZ that he is pictured in the GT ads with? I somehow got the idea that he was borrowing yours. Did the Doc build him one just like yours ? PDW The amp in the ads is Carl's. Mine and his are slightly different cosmetically. The GT ad is here - www.groovetubes.com/assets/1769_gt_verheyen_large.jpgHis has black knobs. Mine has white knobs and was the one that we originally used to A/B against his Marshall Plexi 50 watter. The two amp are set up identically with the same output tubes, bias, but in the front end the pramp tubes are slightly different. Mine has three long plate Ei 7052's and Carl's has Svetlanas that were also had traced. In Carl's amp this can change depending on project. The long smooth plate Ei's can go physically microphonic way too easily to be used in his hard worked amps that move all over the planet. This weekend we may be changing some things in his amp again. Carl's second SRZ-65 is one of the new batch Limited Edition amps I believe. I have not seen his new amp but he should have it in the next few days. That amp will reside in Europe for his rig over there. He has his USA rig and his Europe rig so things do not have to be shipped back and forth as he tours extensively in Europe.
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SG123
Full Member
Posts: 221
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Post by SG123 on Feb 5, 2007 18:10:58 GMT -7
We anxiously await your experimental data.
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Post by myles on Feb 6, 2007 9:28:36 GMT -7
We anxiously await your experimental data. Actually ... I will probably just post a bit of dry technical data and try to talk Carl into doing a bit of a writeup on how things were before and after in a manner of speaking. I am just the mechanic on the car ... he is the driver
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Post by carlverheyen on Feb 21, 2007 9:38:46 GMT -7
Here is an exerpt from an article I recently wrote for an Italian guitar magazine. Hopefully it tells my non-technical side of the tone quest...... Many of my US based amps are vintage, especially the Marshalls, Fenders and Voxes. One amp that I have found to be exceptionally good for distortion and especially for solos is the 1968 vintage Marshall JMP 50 watt head. For some reason this is an amp that is perfectly matched to my playing style, my favorite guitars and my pedals. I have 2 other 60’s era plexi Marshalls, but this one is special. Last year, before a west coast California tour I went looking for a second one and found the value had gone way up. They now wanted $5,500.00 US for this head and, since I want to be making records with it for the rest of my life I realized it was just too valuable to take on the road. This is becoming a big problem for those of us who like to use vintage gear. Many of the modern, high gain heads have a scratchy high end that I don’t want, and the master volume that today’s manufacturers insist upon including kills the touch sensitivity that the old classic amps are known for. Remember, touch sensitivity comes from the power tubes, not the preamp tubes. The minute you try to get all your gain from the preamp section and turn down the power section (via the master volume) you lose the “touch” part of your playing, which is a big part of your individuality. I know it’s all a matter of personal taste, but I prefer a fat, warm distortion sound with my Strats that I can shape and control with my hands. If the amp has a master volume I usually turn it all the way up so it’s hopefully out of the signal path. Myles Rose, my good friend and amp tech told me I could replace that sweet Marshall tone with something currently manufactured, and suggested I check out Dr Z's SRZ-65. After listening to it I found it had the same essential qualities as my ’68 Plexi Marshall, but not quite enough clean headroom. With my 50 watt Marshall I can run the volume at 6 before it really starts to breakup and get crunchy. But here is why a knowledgeable amp tech is so important to my sound. We set up the amp with my complete live rig, meaning with the actual cabinets, snakes and pedal board that I use live. Using various types of tubes in the preamp section we were able to get the right amount of highs, lows and mids needed to make my favorite live guitar sound exactly what I hear in my head. The perfect singing Strat sound seemed to come from the long plate tubes. Then we dealt with the power section and, although I was reluctant to give up the EL-34 power tubes that are a big part of the Marshall sound, we found that KT77s worked better. I realize that KT77s are basically an EL34, but they delivered more clean headroom which meant I could run the amp louder if necessary and use my pedals to get “over the top” when soloing. After biasing the amp and putting it back together we wrote down all the tube model numbers and bias numbers thereby keeping a record of exactly how this amp was customized to my specifications. The problem is: I can only use this head in the USA unless I ship it to Europe and run it through a step-down transformer. Since shipping is expensive and the transformer introduces a nasty 50 cycle hum to your sound there was only one option: Buy another one with a European transformer! It arrived last week and using all the notes we’d taken on the first model, we spent the entire morning last Saturday making it sound exactly the same. Finding your sound is a life-long process. Technology changes, your ears change and what sounded great to you last year may not sound that good next year. It’s a constant quest that the best players take very seriously. Don’t compromise! Realize you can have what you want; you just need know what you want. Find a good tech and try to describe the sound you hear in your head. For years my favorite Strat sound was “Voodoo Chile” from Jimi Hendrix’s Electric Ladyland, but I’ve always liked Dave Gilmour and SRV and Ry Cooder and Mark Knopfler and Eric Johnson and……the list goes on and on. Over the years I have come to find my own sound, but the journey never stops, it just gets more defined. I now prefer the smooth top end of the SRZ-65 over my vintage Marshalls........who would have guessed?
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Post by myles on Feb 21, 2007 10:13:38 GMT -7
As a side note .... In each of Carl's SRZ-65's the preamp tubes were picked based on swapping them in and out of the amps for tubes of different types and specs. I generally choose preamp tubes for Carl's amps based on his playing dynamics and guitars. What he uses may not be applicable for a particular application for others unless you have his hands and his guitars. I generally prefer long plate phase inverters. The 12AX7R2 (Sovtek 12AX7LPS) is used by me in many of Carl's amps and these are matched triodes that have a minimum spec of: Transconductance of 1600 (1700+ in Carl's amps). Current of 1.2mA minimum (Most preamp tubes today fall in the 0.8-1.0 range so right off the bat you are at least 20% down on current driving your output tubes if you do not find tubes of proper spec). This is a typical average spec of a 12AX7LPS / R2. As you see it is far below design spec but this is what is trypically found. Gain on all phase inverters in Carl's amps is >90 in the case of 12AX7 Phase inverters. Gain is also far below the spec of 100 in 90%+ of current production tubes. You have to search them out. Below is a typical current curve of the A abd B sides of a typical 12AX7. This is what 95% of them look like. Below is a curve that is almost perfect but this was a tube that was found in the search for Carl's tubes and was rejected due to a lack of smoothness in the ranges where the amp would not have been turned up very high. The amp would not be all that it could be at moderate levels. As a side note on this curve above ... it is better that 95% of what you will find out there. I would have used this tube for many other folks and it would have been spectacular. I wanted something better for Carl in this case as the SRZ-65 is the heart of his rig and one of his most used tones. You can test and pick tubes on conventional tube testers but you will only get a result at one point in the operating range and not over the tube's entire operating range. That is one reason all of the tubes used in Carl's amps have been traced on a vacuum tube curve tracer and have spec sheets and curves for each tube. On output tubes it is the same situation. Long before I came to GT I learned that dynamic matching worked better for me that the commonly used static matching approach. I want to know what the tube does over it's entire operating range and not just at idle. Carl's output tubes were GT-E34LS #6 biased at 65% idle dissapation depending on the amps plate voltage for these amps. I vary between 50% and 70% depending on amp type and some other factors as a side note. We went to the GT-KT77S (the JJ KT77) from GT in a #8 rating. The KT77S is a beam pentode and a bit different but direct replacement for the EL-34. I felt it would be preferred by Carl and in the end it was shown to be the case. I do not want to get too much into V1 and V2. Carl has an assortment of tubes for many of his amps and looks at the differences between long plate, short plate, high TC, low TC, high gain, low gain, etc. as one more part of his tonal palette. He may have a 12AX7R3 in V1 of one of his BF Pricetons for one project with a particular guitar one day and an ECC83S in there the next. Carl has a briefcase full of tubes he takes places in the same way that Brad Paisley is set up with a number of documented tube choices on the road for his amps. I had some initial writing in the thread at drzamplifiers.proboards41.com/index.cgi?board=srz&action=display&thread=1171156181Myles
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Post by benttop (Steve) on Feb 21, 2007 10:14:54 GMT -7
Carl, thanks for taking the time to fill us in on your tone quest. You've given me some ideas for my SRZ-65 here. And thanks Myles for your data as well. Fascinating stuff.
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Post by sonicgator on Feb 21, 2007 11:49:34 GMT -7
Great Stuff Carl and Myles! I continually learn so much from this board, which is great because I'm still seeking that tone in my head and this information is so informative. I know Steve can back me up here too, but I learned a lot about tubes with my THD BiValve and continually swapping them, so I can understand most of what Myles is saying.
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Post by dock66 on Feb 21, 2007 12:44:55 GMT -7
Thanks for taking the time to do these write-ups, Carl and Myles. Great info ,always learn alot from this forum. Thank you for sharing with the rest of us.
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Post by DRZ on Feb 21, 2007 14:48:10 GMT -7
YEAH MAN. Thanks Carl I appreciate the write up and help it will give my customers. Enjoy the SRZ.
Also thanks to Myles his endless search for the perfect tone is an inspiration to me.
DR.Z
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Post by benttop (Steve) on Feb 21, 2007 15:05:48 GMT -7
I have a feeling Mike over at KCANOS is going to be hit with a lot of KT77 orders in a minute... ;D
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Post by skydog958 on Feb 21, 2007 15:15:47 GMT -7
Awesome stuff! Thanks Myles and Carl and of course, the Doc Himself!
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Post by myles on Feb 21, 2007 19:01:52 GMT -7
I'd personally like to thank the Doc for going along with the idea to bring back the SRZ-65 for a limited run after the amp had been out of production for such a long time. It was an amp that was just ahead of it's time.
Thanks Doc!
And ......... thanks to Carl who is the most versitile player on the planet and has the ability and inventory to play anything I can ask him to play to try out these ideas on various amps.
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Post by myles on Feb 21, 2007 19:15:28 GMT -7
Most people know how much I hate sound clips and MP3's ... so here is the real thing! .... if you want to hear the SRZ-65 in action listen to the entry song on the Carl Verheyen website at www.carlverheyen.comThe song is called "In the stream" and that is pure SRZ-65 fed by a 1958 Strat with a maple neck and is 100% original other than a 5 way switch. You can get your own copy of the CD at www.carlverheyen.com/store.htmHere is some info on the CD: Take One Step Take One Step was a long record to make. Although 2 years were involved in the writing and recording, part of the music actually originated 28 years ago. In the late 70s I worked with a jazz quartet and wrote instrumental music using acoustic piano and fretless bass. We envisioned ourselves as a west coast Pat Metheny Group with synthesizers and a modern sound, improvising over non-swing rhythms and playing long, complex pieces. By 1980 I had moved on from that music, more inspired by my rock roots and blues players like Albert King and Mike Bloomfield. But I never regret the time spent working in an acoustic environment with great musicians and like-minded improvisers. To this day I still surround myself with players that have a similar background because the extended knowledge of harmony and rhythms is such an inspiring place to take rock, blues and popular music. Fast forward to 2004. I was doing a recording session in LA with the brilliant bass player Dave Marotta, a CVband mate from those early days. Dave asked if I ever played “Travel Stories,” an 11 minute, 12 page chart from the late 70s that I composed. I told him that we didn’t, it was probably dated and a bit too jazzy for the band. But he reminded me that there were some nice themes in that song, and suggested that I really should revisit it. When I found the chart and played through it after all those years I found Dave to be right: there were a handful of themes that were quite nice, but the overall sense of the tune was wrong for the band in the 21st century. I began to rewrite using the best parts and combining them with new material (and lyrics) from my current work. The resulting song is the 11 and a half minute centerpiece of the record called Bells of April. I can still hear all the influences, from those early days to the present……. Georgia’s Reel came out of a jam at my house with Cliff Hugo. His unique talent is always inspiring, and one could sit with him daily for many years and mine his deep reservoir of grooves and bass lines. Lyrically the song uses the great American painter Georgia O’Keeffe as an example of an artist creating work for all time and not just within the popular fashion of present day culture. My favorite music never becomes old, is not based on soon-to-be-dated technology and sounds as fresh today as it did when it was created. I believe the best art holds up in a similar way. In fact, this CD was more collaborative than most for me, and I think the end result is a richer and more interesting musical journey. Although the songs are usually my initial concept, The Code and You Bring Me Down were also co-written with Cliff. We benefited by production and arrangement help from Chad Wackerman, especially in setting up the signature groove for The Code. His playing on the title tune Take One Step is breathtaking, and his jump into hyper-drive after the 2nd chorus is a powerful moment. Bernie Dresel plays a deep shuffle on songs like Lighthouse and In the Stream. His sense of swing and constant propulsion is something rare in modern rock drummers, but knowing his background it’s only fitting that he understands that part of the music so well. We cut the entire song In the Stream live in the studio with no overdubs or fixes, and that was Bernie’s 2nd take. The first take was just to learn it! Topanga Hoedown is an up tempo instrumental piece that leans towards the pastoral edge of country music. Most of that tune is live, too….we kept the original guitar solo from the basic track which gives it that edge-of-your-seat feel. Dusk (parts 1 & 2) was recorded after midnight following a long day of tracking. We decided to open all the doors and let the amplifiers bleed into the drum mics for that big open sound on the basic track. Background vocals and Jim Cox’s beautiful Hammond B-3 were overdubbed, but it wasn’t until Naomi Star sang her harmony and soulful vocal improvised lines that the song really began to take on a new life. I am very fortunate to be close friends with all the musicians and singers that worked on Take One Step. I have been playing music with Jim Cox and Chad Wackerman since the 70s, and Craig Copeland, Mark Hart, Cliff Hugo, Bernie Dresel, Naomi Star and I go back to the early 80s together. There is something very rewarding about strong, long lasting musical relationships, because in our business we have more than our share of casual musical relationships. For me, this record is a celebration of those friends and their unique talents. Their support of my music shines through on every song, and this is a gift I will forever appreciate. Carl Verheyen 2006
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Post by sonicgator on Feb 21, 2007 20:57:18 GMT -7
Wow, that's sound great toneage! It's always great to hear someone using the same piece of gear I have and making it sound like it can and should!
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